Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

why can't I open pdf files in firefox anymore?

more options

When opening pdf files it will only go in a loop and won't stop making new tabs. The only way to stop this is by clicking on the home button several times or close firefox

When opening pdf files it will only go in a loop and won't stop making new tabs. The only way to stop this is by clicking on the home button several times or close firefox

All Replies (1)

more options

It depends. When a server says that a file is of the application/pdf content type, it should load in the built-in PDF viewer, or in the Adobe plugin. However, if the server says it is a different content type, even if it has a .pdf extension, directing Firefox to open it can lead to an infinite loop of more and more tabs or windows opening.

The typical strong medicine for this is to rename the settings file that associates the problem content type with Firefox. This also will delete any past associations created for different content types and revert to the default.

Open your current Firefox settings (AKA Firefox profile) folder using either

  • "3-bar" menu button > "?" button > Troubleshooting Information
  • Help menu > Troubleshooting Information

In the first table on the page, click the "Show Folder" button

Leaving that window open, switch back to Firefox and Exit, either:

  • "3-bar" menu button > "power" button
  • File menu > Exit

Pause while Firefox finishes its cleanup, then rename mimeTypes.rdf to something like mimeTypes.old

Start Firefox back up again and you should get the standard behavior. This time, if Firefox doesn't know how to handle a PDF, please do not redirect it to open in Firefox. (If Firefox knows how to handle it, it won't pop the question in the first place.)

If I've misunderstood what happened, could you give a link to the problem download?

Removed stray text from copy/paste error.

Modified by jscher2000 - Support Volunteer