Suddenly cannot access PDF files

try this

1. Check Your PDF Viewer Settings: If you're using Adobe Acrobat Reader as your default PDF viewer, make sure it hasn't undergone any unexpected changes. Open Adobe Acrobat Reader, go to the "Edit" menu (on Windows) or "Adobe Acrobat Reader" menu (on macOS), and select "Preferences" or "Preferences...". decor Look for relevant settings that might be causing the issue.

2. Update Adobe Acrobat Reader: Ensure that you are using the latest version of Adobe Acrobat Reader. Older versions might have compatibility issues, and updating to the latest version can often  resolve such problems.

3. Check File Associations: Make sure that the PDF file type is associated with Adobe Acrobat Reader. To do this:
- On Windows: Right-click on a PDF file, choose "Open with," and select "Choose another app." Then, select Adobe Acrobat Reader and check the box that says "Always use this app to open .pdf files."
- On macOS: Right-click on a PDF file, choose "Get Info," expand the "Open with" section, and select Adobe Acrobat Reader. Click "Change All..." to ensure all PDFs open with Adobe Acrobat Reader.

4. Clear Cache and Temporary Files: Sometimes, corrupted cache or temporary files can cause issues. Clear the cache and temporary files of Adobe Acrobat Reader to see if that resolves the problem.

5. Check Security Software: Certain security software or antivirus programs may interfere with PDF files. Temporarily disable any security software and see if you can access the PDF files.

6. Test with Other PDF Readers: Try opening the PDF files with alternative PDF readers like Foxit Reader or Sumatra PDF. This will help you determine if the issue is specific to Adobe Acrobat Reader.

7. Restart Your Computer: A simple restart can often resolve unexpected software issues.

8. Reinstall Adobe Acrobat Reader: If the problem persists, consider uninstalling Adobe Acrobat Reader and then reinstalling the latest version from the official Adobe website.

9. Check PDF File Integrity: Verify if the specific PDF files you are trying to open are intact and not corrupted. Try opening other PDF files to see if they open correctly.

If none of these steps resolve the issue, it's possible there might be a more complex problem with your system or the PDF files themselves. In such cases, seeking technical support from Adobe or an IT professional might be necessary.

Remember to back up any important PDF files before attempting any significant changes to your system.

Right-click the PDF, pick Open With > Choose default program (or Choose another application in Windows 10). Pick Adobe Acrobat Reader DC or Adobe Acrobat DC in the rundown of projects, and afterward do one of the accompanying: (Windows 7 and prior) Select Always utilize the chose program to open this sort of document