Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

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

cannot launch firefoex browser

  • 3 replies
  • 5 have this problem
  • 1 view
  • Last reply by cor-el

more options

when i click on firefox I get a pop up saying XULrunner error platform version 120.0.1 not compatible with min version => 120.0 max version =<120

when i click on firefox I get a pop up saying XULrunner error platform version 120.0.1 not compatible with min version => 120.0 max version =<120

All Replies (3)

more options

sorry firefox

more options

Has anyone launching firefox have this issue

more options

An error message like XPCOM missing or about platform version or entry points not found can happen because of a failed Firefox update that left you with a mixture of old and updated files in the Firefox installation folder. This can happen in case security software was keeping a handle of some of the files in the Firefox program folder preventing Firefox from replacing all the files. You need to do a clean reinstall and remove the Firefox program folder to ensure that all files are replaced. You may have to disable security software temporarily in case the problem persists.