There could be several reasons why your PDF file is not displaying in your browser. Here are some possible causes and solutions:

• Outdated Browser
  • Solution: Update your browser to the latest version.
• PDF Viewer Plugin
  • Solution: Make sure the PDF viewer plugin is correctly installed and enabled. Some browsers have a built-in PDF viewer; others require an external plugin.
• Browser settings
  • Solution: Check your browser settings and make sure PDF files are allowed to open.
• Damaged PDF file
  • Solution: Open the PDF file with a PDF reader such as Adobe Acrobat Reader to check its integrity.
• Cache Problem
  • Solution: clear cache and cookies and reload the page.
• Pop-up blockers
  • Solution: temporarily disable pop-up blockers or extensions.
• Internet connection
  • Solution: Check and upgrade your internet connection if necessary.
• Compatibility problems
  • Solution: Try another browser to see if the problem occurs there too.

Steps to take

1. Update your browser.
2. Check the PDF viewer plugin.
3. Check browser settings.
4. Check the PDF file with a PDF reader.
5. Clear cache and cookies.
6. Disable pop-up blockers.
7. Check your internet connection.
8. Try a different browser.
   

If you still have problems after these steps, please provide more details about your browser and the problem for targeted support.