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 will not start

  • 5 replies
  • 1 has this problem
  • Last reply by jchauhan

more options

When I try to start Frefox I get the following error message

The instruction at "0x7b9777a9" referenced memeory at "0x7b9777a9". The memory could not be "read".

Click OK to terminate the program.

When I try to start Frefox I get the following error message The instruction at "0x7b9777a9" referenced memeory at "0x7b9777a9". The memory could not be "read". Click OK to terminate the program.

All Replies (5)

more options

Hopefully this support article is what you need:

https://support.mozilla.com/en-US/kb/Firefox+will+not+start

more options

Thanks for the help - this unfortunately did not resolve my problem.

more options

Can you please try it in a new (temporary) Firefox profile and see if the issue is still present? See this article to know how to create a new Firefox profile. Please report back the results.

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" (Mac: "Firefox > Quit"; Linux: "File > Quit")

more options

Thank you to everyone who provided me with help on this. I tried pretty much everything suggested and in the end decided to reformat C-drive and start all over again.