Firefox Community Forum

This problem just started with the latest version of Firefox that opens with two profiles. It worked for a short time and then failed. Firefox will not open if I choose the default profile. I can open Firefox if I choose Profile #2, but it has none of the history of the default profile. I lose all of my extensions, history, bookmarks - everything.

How can I get back to where I was yesterday? (Note: I'm just a user, not a computer geek, and don't understand the buzzwords or technospeak. I can follow clear instructions like copy, delete, rename, etc.)

I'm using an HP laptop with Windows 11.

New laptop. Installed Firefox. Set up 2 of the "new" type profiles. Typical extensions (Bitwarden, Bit.ly, Firefox Color). Not too long after, Firefox will no longer launch and the only remediation I've found is to do a clean uninstall/reinstall including deleting registry keys. I've now done this three times now. Environment information

• i7 Core Ultra/32GB RAM
• SentinelOne - Corporate Environment. Installs Firefox Extension. There are no signs in the S1 portal or client that it is blocking firefox.
• nVIDIA RTX PRO 500 Blackwell Video Card. Updated to current driver 582.16
• Threatlocker - Computer is new and has been in "Learning Mode" so it isn't an issue
• Tailscale runs on this machine, but it doesn't seem to make a difference if it is running.

Nothing in the %APPDATA% crash reports folder for firefox. Crash dumps for firefox are in %LOCALAPPDATA%/CrashDumps. One read by AppCrashView is attached. It is a 0xc0000005 Access violation in StackHash_2264.

This is a problem where renaming the firefox.exe to firefox1.exe will get it to run but it seems to lose track of profiles.

Firefox is my favorite browser and I'd like to resolve this, but I really can't afford spending much more time on it or continually clean reinstalling and rebuilding profies. I've seen other similar posts, but no clear resolution.