How to Fix PDF Files That Won't Open: Complete Guide

Table of Contents

  1. Introduction
  2. Understanding PDF Files and Common Issues
  3. Diagnosing Why Your PDF Won't Open
  4. Quick Solutions to Try First
  5. Comprehensive PDF Repair Methods
    1. Method 1: Use Alternative PDF Readers
    2. Method 2: Open in Web Browsers
    3. Method 3: Use Adobe's PDF Repair Tools
    4. Method 4: Extract Content from Corrupted PDFs
    5. Method 5: Recreate the PDF
    6. Method 6: Use Professional PDF Recovery Software
    7. Method 7: Online PDF Repair Services
  6. Solutions for Specific PDF Error Messages
  7. Dealing with Password and Security Issues
  8. How to Prevent PDF Opening Problems
  9. Conclusion

Introduction

PDF (Portable Document Format) files are designed to be universally accessible, maintaining consistent appearance across different devices and platforms. Their reliability and compatibility have made them the standard format for sharing documents, from business contracts and government forms to academic papers and digital books.

However, despite their robust design, PDFs can sometimes refuse to open. You might encounter error messages, see only a blank page, or experience application crashes when attempting to access important PDF documents. These issues can stem from various causes, including file corruption, compatibility problems, security settings, or software limitations.

This comprehensive guide explores multiple approaches to fixing PDF files that won't open. We'll cover everything from simple troubleshooting steps to advanced recovery techniques, providing you with a complete toolkit for regaining access to your valuable PDF documents.

Whether you're dealing with a corrupted business contract, a damaged academic paper, or any other PDF that refuses to open, you'll find practical, step-by-step solutions here. We'll also share preventive measures to help you avoid similar issues in the future and ensure your important documents remain accessible when you need them.

Understanding PDF Files and Common Issues

To effectively troubleshoot PDF opening problems, it's helpful to understand the fundamental structure of PDF files and why they might become inaccessible.

What Makes a PDF File Unique

The PDF format was created by Adobe in the 1990s and has since become an open standard. Key characteristics include:

PDF File Structure

A PDF file consists of several key components:

This structure is important to understand because damage to specific components can cause different types of opening failures. For instance, a corrupted header might prevent the file from being recognized as a PDF, while problems with the cross-reference table might result in partial loading or missing content.

Common Causes of PDF Opening Problems

PDFs can fail to open for numerous reasons:

PDF Versions and Compatibility

The PDF specification has evolved over time, with newer versions adding features that older readers might not support:

A PDF created with newer specifications may display incorrectly or fail to open in older PDF readers. Similarly, PDFs with specialized features like 3D content or advanced form functionality might not work properly in basic readers.

PDF Readers and Their Differences

Not all PDF readers are created equal. They vary in their:

This diversity in PDF readers means that a file that won't open in one application might work perfectly in another—a fact we'll leverage in our recovery methods.

Diagnosing Why Your PDF Won't Open

Before attempting repairs, it's helpful to identify the specific reason your PDF won't open. Different symptoms and error messages can point to different underlying issues.

Common Error Messages and Their Meanings

Common Behavioral Symptoms

When no specific error message appears, observe how the PDF reader behaves:

Quick Diagnostic Checks

Perform these quick checks to help identify the problem:

  1. Check file size:
    • A zero or extremely small file size (a few bytes) suggests the file is critically damaged or empty
    • An unusually large file (hundreds of MB or more) might exceed reader capabilities
  2. Verify file extension: Ensure the file has a .pdf extension and wasn't renamed from another format
  3. Check download completion: If recently downloaded, verify the download completed successfully
  4. Try another PDF reader: Test if the issue is specific to one application
  5. Examine file source: Consider how and where you obtained the file—was it from a reliable source?
  6. Check for security software interference: Antivirus or firewall software might be blocking access

Understanding the specific nature of your PDF problem will guide you to the most appropriate solutions in the following sections.

Quick Solutions to Try First

Before diving into more complex repair methods, try these quick, simple approaches that often resolve PDF opening issues:

1. Update Your PDF Reader

Outdated PDF readers may not support newer PDF features or may contain bugs that prevent certain files from opening:

  1. Check if updates are available for your PDF reader
  2. For Adobe Acrobat Reader DC, go to Help > Check for Updates
  3. For other readers, check their websites or app stores for the latest versions
  4. Install any available updates and restart your computer
  5. Try opening the PDF again

2. Try a Different PDF Reader

Different PDF readers have varying levels of tolerance for file issues:

  1. If you're using Adobe Reader, try alternatives like:
  2. If using an alternative reader already, try Adobe Acrobat Reader DC
  3. Install one of these alternatives and attempt to open your PDF

3. Clear Browser Cache (For Web-Viewed PDFs)

If you're trying to view a PDF in a web browser, cached data might be causing problems:

  1. Open your browser settings
  2. Find the option to clear browsing data/history
  3. Select to clear cached images and files
  4. Reload the page containing the PDF link

4. Download the File Again

If the PDF was downloaded from the web, the download might have been interrupted or corrupted:

  1. Return to the source website
  2. Download the PDF again
  3. If possible, try a different browser for the download
  4. Save it with a new name to avoid conflicts with the corrupted version
  5. Attempt to open the fresh download

5. Copy the File to a Local Drive

Network or external drive issues can sometimes interfere with PDF opening:

  1. If the file is on a network drive, external hard drive, or USB flash drive, copy it to your local hard drive
  2. Try opening the local copy
  3. If successful, this suggests connection or permission issues with the original location

6. Restart Your Computer

Simple but effective, restarting can clear memory issues and reset system resources:

  1. Save any open work
  2. Restart your computer completely
  3. After restart, try opening the PDF again

7. Open in a Web Browser

Modern web browsers have built-in PDF viewers that sometimes handle problematic files better:

  1. Right-click the PDF file
  2. Select "Open with" and choose your web browser (Chrome, Firefox, Edge, etc.)
  3. Alternatively, drag and drop the PDF file directly into an open browser window
  4. If it opens, you can save or print from the browser

8. Check for File Locks or Permissions

File permission issues can prevent PDFs from opening properly:

  1. Right-click the PDF file and select Properties
  2. Check if the file is marked as "Read-only" or has restricted permissions
  3. Uncheck the "Read-only" attribute if present
  4. On Windows, click the "Security" tab and verify you have read permissions
  5. On Mac, click the padlock icon in the info window and adjust permissions if needed
  6. Click "Apply" or "OK" to save changes
  7. Try opening the file again

9. Disable Protected View (Adobe Reader)

Adobe's Protected View can sometimes block legitimate PDFs:

  1. Open Adobe Reader
  2. Go to Edit > Preferences (Windows) or Acrobat/Reader > Preferences (Mac)
  3. Select "Security (Enhanced)" from the categories
  4. Temporarily uncheck "Enable Protected Mode at startup"
  5. Click OK and restart Adobe Reader
  6. Try opening the PDF
  7. Important: Re-enable Protected Mode after troubleshooting for security

10. Try Opening on a Different Device

Sometimes the issue is device-specific rather than file-specific:

  1. Transfer the PDF to another computer, tablet, or smartphone
  2. Attempt to open it on the different device
  3. If it opens successfully, the issue might be with your original device's software or settings

These quick solutions resolve many common PDF opening issues. If your file still won't open, proceed to the more comprehensive repair methods in the next section.

Comprehensive PDF Repair Methods

When quick solutions don't work, these more comprehensive methods can help recover your PDF files:

Method 1: Use Alternative PDF Readers

Different PDF readers use different rendering engines and have varying levels of tolerance for file corruption. If basic readers fail, specialty readers might succeed:

Advanced PDF Readers to Try:

  • PDF-XChange Editor
    • Known for handling problematic PDFs well
    • Has a free version with basic functionality
    • Includes built-in repair options
  • Nuance Power PDF
    • Commercial software with strong repair capabilities
    • Good at handling structural issues in PDFs
  • Sumatra PDF
    • Lightweight reader that often opens files others can't
    • Less strict about PDF specification conformance
    • Completely free and portable (no installation required)
  • Okular
    • Open-source reader with high tolerance for PDF problems
    • Available for multiple platforms
  • PDF Studio
    • Professional-grade PDF software
    • Includes advanced repair features

Steps:

  1. Download and install one of these alternative readers
  2. Attempt to open your problematic PDF
  3. If it opens, use the reader's "Save As" function to create a fresh copy of the document
  4. This new copy may open in your regular PDF reader

Success Rate: Moderate, varies by specific PDF issue.

When It Works Best: This method is particularly effective for PDFs with minor corruption, format compatibility issues, or when specific features in the PDF are causing problems in your usual reader.

Limitations: Severely corrupted files may not open in any reader. Some alternative readers may display content differently or not support all interactive features.

Method 2: Open in Web Browsers

Modern web browsers have sophisticated built-in PDF engines that can sometimes handle problematic files better than dedicated PDF readers:

Recommended Browsers:

  • Google Chrome: Has a robust PDF viewer based on the PDFium project
  • Mozilla Firefox: Uses PDF.js, which can handle some types of corruption well
  • Microsoft Edge: The newer Chromium-based Edge has excellent PDF capabilities
  • Brave: Based on Chromium with similar PDF handling strengths

Direct Opening Method:

  1. Right-click on the PDF file
  2. Select "Open with" and choose your preferred browser
  3. If it opens successfully, use the browser's print function to save as a new PDF

Drag and Drop Method:

  1. Open your web browser
  2. Open a new, empty tab
  3. Drag and drop the PDF file directly into the browser window

URL Method:

  1. In your browser's address bar, type: file:/// followed by the full path to your PDF
  2. For example: file:///C:/Users/Username/Documents/example.pdf
  3. Press Enter to load the file

Saving from Browser:

If the PDF opens in a browser but not in a regular PDF reader:

  1. Use the browser's print function (Ctrl+P or ⌘+P)
  2. Select "Save as PDF" or "Microsoft Print to PDF" as the printer
  3. Save the file with a new name
  4. Try opening this newly created version in your PDF reader

Success Rate: Moderate, especially for minor corruption.

When It Works Best: Browser-based PDF viewers are particularly good at handling files with minor structural issues, partially downloaded PDFs, or those with compatibility problems.

Limitations: Browser viewers may not support all interactive features like forms and JavaScript. They also might struggle with very large or complex PDFs.

Method 3: Use Adobe's PDF Repair Tools

As the creator of the PDF format, Adobe offers several built-in options for repairing damaged files:

Acrobat's Preflight Tool (Acrobat Pro only):

  1. Open Adobe Acrobat Pro DC
  2. Go to Tools > Print Production > Preflight
  3. In the Preflight dialog box, select "PDF fixups" in the library
  4. Choose "Repair PDF structure"
  5. Click "Analyze and fix"
  6. Select your problematic PDF file
  7. Save the repaired file with a new name

Using Print Production Tools (Acrobat Pro only):

  1. Open Acrobat Pro DC
  2. Go to Tools > Print Production
  3. Click on Flattener Preview or Transparency Flattener
  4. Select your problematic PDF (if possible)
  5. Apply flattening to create a simpler version of the document
  6. Save as a new file

Adobe's Online "Create PDF" Service:

  1. Go to Adobe's Online PDF Creator
  2. Upload your problematic PDF
  3. The service will attempt to process and regenerate the PDF
  4. Download the result

Using Adobe Reader's Save As Method:

If the PDF opens at all, even with errors or problems:

  1. Open the file in Adobe Acrobat Reader
  2. Go to File > Save As
  3. Save with a new name
  4. This process sometimes rebuilds problematic parts of the file

Success Rate: Moderate to high for Adobe-created PDFs with minor issues.

When It Works Best: These methods work particularly well for PDFs created with Adobe products or those with structural issues that don't affect the core content. The Preflight tool is especially effective for professional documents with specific compliance issues.

Limitations: The most powerful repair tools require a paid Acrobat Pro subscription. Severely corrupted files might not be repairable with these methods.

Method 4: Extract Content from Corrupted PDFs

If you can't repair the PDF structure, you might still be able to extract its content:

Text Extraction Methods:

Using Copy-Paste (if PDF partially opens):
  1. If any portion of the PDF opens, try selecting all content (Ctrl+A)
  2. Copy the selected content (Ctrl+C)
  3. Paste into a word processor (Ctrl+V)
  4. Save in your preferred format
Using Text Extraction Tools:
  1. Try dedicated text extraction tools:
  2. Upload your PDF to the chosen service
  3. Download the extracted text content
Command-line Text Extraction (Advanced):
  1. Install Xpdf tools or Poppler
  2. Use the 'pdftotext' utility:
    • Open Command Prompt or Terminal
    • Run: pdftotext corrupted.pdf extracted.txt
  3. Check the resulting text file for recoverable content

Image Extraction Methods:

Using Image Extraction Tools:
  1. Try online services:
  2. Upload your PDF
  3. Download the extracted images
Using PDF Readers with Image Export:
  1. Some PDF readers like PDF-XChange Editor allow direct extraction of images
  2. Look for options like "Export All Images" in the tools or export menu
  3. Save the extracted images
Screenshot Method (Last Resort):
  1. If the PDF partially opens in any viewer, take screenshots of visible content
  2. Use screen capture software for better quality
  3. Save the screenshots as image files

Recreating from Extracted Content:

  1. Combine the extracted text and images in a word processor
  2. Recreate the document's format as closely as possible
  3. Save or export as a new PDF

Success Rate: Varies depending on the type and extent of corruption.

When It Works Best: This approach is particularly useful when the document's content is still intact but the PDF structure is too damaged to repair. It's best for text-heavy documents where formatting isn't critical.

Limitations: Original formatting, layout, and interactive elements will be lost. Text extraction can fail with heavily image-based PDFs or those using non-standard fonts.

Method 5: Recreate the PDF

If you have access to the original source files or can recreate the content, generating a fresh PDF is often the most reliable solution:

From Original Source Files:

  1. Locate the original document (Word, Excel, PowerPoint, etc.)
  2. Open in the appropriate application
  3. Use File > Export or Save As > PDF
  4. Configure PDF options for optimal quality
  5. Save the new PDF with a different name

Print to PDF Method:

If the file opens partially in any application:

  1. Open the damaged PDF in any viewer that can display it, even partially
  2. Use the Print function (Ctrl+P or ⌘+P)
  3. Select "Microsoft Print to PDF," "Save as PDF," or similar
  4. Configure print settings for best quality
  5. Save the new PDF file

Using Online Converters:

  1. If you have the source file in another format, use online conversion services:
  2. Upload your source document
  3. Download the converted PDF

Scanning Physical Copies:

If you have a printed version of the document:

  1. Scan the physical pages using a scanner or smartphone scanning app
  2. Save directly as PDF or convert the scanned images to PDF
  3. Use OCR (Optical Character Recognition) if you need searchable text

Document Recreation Services:

For critical documents without source files:

  1. Consider professional document recreation services
  2. Freelancers on platforms like Upwork or Fiverr can recreate documents from partial information
  3. Specify that you need a PDF as the final deliverable

Success Rate: High, assuming you have the original content.

When It Works Best: This approach is ideal when source files are available or when the document can be easily recreated. It's particularly appropriate for important documents where having an exact, reliable copy is crucial.

Limitations: Requires access to original content, which may not always be available. Recreating complex documents can be time-consuming.

Method 6: Use Professional PDF Recovery Software

When built-in methods fail, dedicated recovery software can often salvage severely corrupted PDF files:

Recommended Recovery Software:

  • Stellar Repair for PDF
    • Specializes in repairing corrupted PDF files
    • Recovers text, images, graphs, and other content
    • Preview feature allows you to verify results before purchase
    • Available for both Windows and Mac
  • DataNumen PDF Repair
    • High success rate with severely damaged PDFs
    • Recovers text, images, and formatting
    • Supports batch processing of multiple files
  • Recovery Toolbox for PDF
    • User-friendly wizard interface
    • Recovers internal file structure
    • Handles various corruption scenarios
  • Wondershare Repairit PDF
    • Multi-platform support
    • High success rate with complex documents
    • Repairs password-protected PDFs
  • Kernel for PDF Repair
    • Restores corrupted PDF objects
    • Preserves hyperlinks and other interactive elements
    • Supports all PDF versions

General Steps for Using Recovery Software:

  1. Download and install your chosen recovery software
  2. Launch the application
  3. Select or browse for your corrupted PDF file
  4. Start the scanning/repair process
  5. Preview the recoverable content (if the software offers this feature)
  6. Save the repaired PDF to a new location

Success Rate: High for most types of corruption.

When It Works Best: Specialized recovery software is particularly effective for severely corrupted files that won't open with any of the previous methods. These tools use advanced algorithms specifically designed to rebuild PDF file structures and extract content from damaged files.

Limitations: Most professional tools require payment, though many offer free trials with preview functionality. Even with specialized software, recovery of extremely damaged files may be partial.

Method 7: Online PDF Repair Services

Online services offer convenient PDF repair without installing software:

Recommended Online Repair Services:

  • Sejda PDF Repair
    • Simple interface with drag-and-drop functionality
    • Free for basic usage with daily limits
    • No software installation required
  • PDFRecover
    • Specializes in fixing structurally damaged PDFs
    • Pay-per-use model
    • Provides a preview of recoverable content
  • PDF24 Tools
    • Free online service
    • Simple, user-friendly interface
    • Deletes uploaded files after processing
  • iLovePDF Repair
    • Part of a comprehensive suite of PDF tools
    • Free for basic repairs
    • Premium subscriptions for enhanced features
  • Office Recovery Online
    • Free preview with paid recovery
    • Handles multiple types of PDF corruption
    • No installation required

General Steps for Using Online Services:

  1. Visit the online repair service website
  2. Upload your corrupted PDF file
  3. Wait for the service to process your file
  4. Preview the recovered content if available
  5. Complete any required payment (if applicable)
  6. Download the repaired PDF

Privacy Considerations:

When using online services:

  • Be cautious with confidential or sensitive documents
  • Review the service's privacy policy
  • Look for services that mention secure file handling and automatic deletion
  • Consider using a service that offers encryption during transmission

Success Rate: Moderate, varies by service and corruption type.

When It Works Best: Online services are convenient for occasional repairs, especially when you don't want to install software. They work best for moderately corrupted files and situations where privacy isn't a major concern.

Limitations: File size limits often apply (typically 10-100MB). Privacy concerns exist with confidential documents. Some services offer limited features in their free versions.

Solutions for Specific PDF Error Messages

Certain PDF errors have specific solutions. Here are targeted approaches for common error messages:

"There was an error opening this document. The file is damaged and could not be repaired."

  1. Try Alternative Readers: Sumatra PDF or PDF-XChange Editor often handle this error better
  2. Use Recovery Software: This is a prime case for dedicated PDF repair tools from Method 6
  3. Extract Content: If repair fails, try Method 4 to extract whatever content is still accessible
  4. Check for Zero-Byte Files: If the file size is 0 KB, the file is likely unrecoverable
  5. Re-download: If recently downloaded, try acquiring the file again from the source

"File does not begin with '%PDF-'"

  1. Check File Type: This error suggests the file might not actually be a PDF despite its extension
  2. Open with Notepad: View the file in a text editor to check if it contains readable text
  3. Try Different Extensions: If you see HTML or other content types, try changing the extension accordingly
  4. Check for Download Issues: The file might be a download placeholder or error page saved with a .pdf extension
  5. Header Repair: Advanced users can try adding the missing PDF header in a hex editor

"The document cannot be opened because it is protected"

  1. Verify Password: Ensure you're entering the correct password, checking case sensitivity
  2. Check with Document Owner: Contact the person who created the PDF for the password
  3. Try Default Passwords: Common defaults like "password," "admin," or the filename itself
  4. Use Alternative Readers: Some readers handle password protection differently
  5. Consider Password Recovery Tools: For legitimate uses where the password is lost

"Please wait...If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document."

  1. Wait Longer: Large or complex PDFs might need more time to render
  2. Update Your PDF Reader: This message often appears with outdated software
  3. Try Alternative Viewers: Browser-based viewers or other PDF applications
  4. Check for JavaScript: The file might contain scripts that are causing the delay
  5. Reduce PDF Complexity: If possible, recreate the PDF with simpler settings

"Some parts of the file are missing or damaged."

  1. Use Open and Repair: In Acrobat, try File > Open > select file > click the dropdown next to Open button > Open and Repair
  2. Content Extraction: Focus on retrieving what's still accessible using Method 4
  3. Check for Partial Downloads: The file might be incomplete; try downloading again
  4. Try Recovery Software: Specialized tools often handle partial damage well
  5. Recreate Missing Parts: If practical, consider recreating the damaged sections

"Insufficient data for an image"

  1. Update PDF Reader: This error often relates to image handling capabilities
  2. Try Online Viewers: Web-based services might render the images differently
  3. Image Extraction: Try extracting and saving just the images from the PDF
  4. Recovery Software: Look for tools specializing in PDF image recovery
  5. Print to New PDF: If parts are viewable, try printing to a new PDF to fix image references

"Font contains glyphs that can't be displayed" or "A font is corrupt or missing"

  1. Font Installation: Try installing the missing fonts on your system if you know which ones
  2. Update Reader: Newer versions often include improved font handling
  3. Print to New PDF: This sometimes embeds or substitutes problematic fonts
  4. Try Different Readers: Some handle font issues better than others
  5. Extract Text: Focus on retrieving the content, even if formatting is lost

"Can't read XRef table" or "XRef table is corrupt"

  1. Professional Repair Tools: This specific structural damage typically requires dedicated software
  2. Try PDF-XChange Editor: Known for handling XRef issues well
  3. Acrobat's Preflight: The "Analyze and fix" option sometimes repairs XRef tables
  4. Command-line Tools: Advanced users can try tools like QPDF or Ghostscript
  5. Online Repair Services: Several specialize in structural repairs like this

Dealing with Password and Security Issues

Password protection and security settings can prevent PDF access. Here's how to deal with these situations:

Types of PDF Security

Understanding the type of protection is important for addressing it appropriately:

Legitimate Password Recovery

For situations where you have the legal right to access the document but have lost the password:

Contact the Document Owner or Creator:

Always the first and most appropriate step:

Try Common or Default Passwords:

People often use predictable passwords:

Check Different Keyboard Layouts:

Password issues can occur with different keyboard configurations:

Removing PDF Restrictions (For Documents You Own)

If you're the legitimate owner and need to remove restrictions from your own PDF:

Using Adobe Acrobat Pro:

  1. Open the PDF in Acrobat Pro
  2. Go to File > Properties
  3. Click the "Security" tab
  4. Click "Security Method" dropdown and select "No Security"
  5. You'll need to enter the permissions password if one exists
  6. Save the document with a new name

Using Online Services (for non-sensitive documents):

  1. Try services like:
  2. Upload your PDF
  3. The service will remove the restrictions
  4. Download the unlocked PDF

Print to PDF Method:

  1. If you can open the file but not edit or copy:
    • Print the document using "Microsoft Print to PDF" or similar
    • The new PDF will typically be free of restrictions
    • Note: This only works for permissions passwords, not document open passwords

Handling Digitally Signed PDFs

For documents with digital signatures that are causing issues:

Enterprise Document Protection Systems

For corporate environments using enterprise rights management:

For these systems, contact your IT department for proper access procedures.

Legal and Ethical Considerations

Always respect copyright and security considerations:

How to Prevent PDF Opening Problems

Preventing PDF issues is always preferable to fixing them. Here are effective strategies to minimize the risk of encountering PDFs that won't open:

Creating Reliable PDFs

File Transfer and Storage Best Practices

Software Maintenance

Security Considerations

Organizational Practices

By implementing these preventive measures, you can significantly reduce the likelihood of encountering PDF files that won't open, saving time and frustration in the long run.

Conclusion

PDF files that refuse to open can be a significant source of frustration, especially when they contain important information. Fortunately, as we've explored throughout this comprehensive guide, multiple pathways exist for troubleshooting and recovering problematic PDFs.

The key to successful PDF recovery is a methodical approach:

  1. Start with the simplest solutions—updating your PDF reader, trying alternative viewers, or simple file operations
  2. Progress to more specialized methods like using web browsers or Adobe's built-in repair features
  3. If necessary, extract content from the PDF or attempt to recreate it
  4. For more severe corruption issues, leverage professional recovery software or online services
  5. Address specific error messages with targeted solutions
  6. For security-related issues, follow appropriate channels to gain legitimate access

Remember that different PDF issues require different approaches. The method that works for one problematic file might not work for another, so patience and willingness to try multiple solutions are essential.

While recovery methods are valuable, prevention remains the best strategy. Creating PDFs properly, maintaining updated software, implementing good file management practices, and keeping appropriate backups can significantly reduce your risk of encountering PDF opening problems in the future.

By combining the troubleshooting techniques and preventive measures outlined in this guide, you'll be well-equipped to handle PDF access challenges and ensure your important documents remain accessible when you need them most.

Need help with other document issues?

Check out our guides for other common document error solutions: