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

Firefox error

  • 1 reply
  • 2 have this problem
  • 2 views
  • Paskiausią atsakymą parašė cor-el

more options

Whenever I start Firefox, an error occurs. A message box pops with "Title : [JavaScript Application]" and the "Message : An error occurred throwing an exception"

This happened

Every time Firefox opened

User Agent

Opera/9.80 (Windows NT 6.1; U; en) Presto/2.5.24 Version/10.53

Whenever I start Firefox, an error occurs. A message box pops with "Title : [JavaScript Application]" and the "Message : An error occurred throwing an exception" == This happened == Every time Firefox opened == User Agent == Opera/9.80 (Windows NT 6.1; U; en) Presto/2.5.24 Version/10.53

All Replies (1)

more options

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of your add-ons is causing your problem (switch to the DEFAULT theme: Tools > Add-ons > Themes). See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems and Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems

If it does work in Safe-mode then disable all your extensions and then try to find which is causing it by enabling one at a time until the problem reappears. You can use "Disable all add-ons" on the Safe mode start window to disable all extensions. You have to close and restart Firefox after each change via "File > Exit" (on Mac: "Firefox > Quit")