The problem is, Firefox window will not open when I try to start it. I can only see a process appear in the task manager, but no window will show up. It used to work fine but something, possibly an update, has broke it. Using Windows 7, Firefox 44.
Things I've tried:
- Start it in safe mode with shift pressed: no impact, same behavior
- Try to start profile manager using firefox.com -P: no impact, same behavior
- Try to remove the binaries from C:\Program Files (x86)\Mozilla Firefox and reinstalling: no impact, same behavior when starting
- Uninstalled Firefox using its own installer, then reinstalled: no impact
- Removed my profile from C:\Users\myusername\AppData\Roaming\Mozilla\Firefox\Profiles: no impact, same behavior when starting
- Removed my profile from C:\Users\myusername\AppData\Local\Mozilla\Firefox\Profiles: on first run after this complained about missing profile; reinstalling Firefox brought back to error behavior
- Rebooted the computer: no impact
- Run a Microsoft Security Essentials scan: no results
- Checked for results in Event Viewer -> Applications, nothing interesting
- chkdsk found no problems
After each test, I've also killed the firefox.exe process using task manager before trying something else.
I'm at loss. I have no more ideas what to try.
Edit: I've now opened a bug to bugzilla about this, as it seems to be an actual bug.
Edit 2: I should have mentioned that I've been using 32-bit version of Firefox on my 64-bit Windows 7. Switching to 64-bit Firefox also made the issue go away.
So as a summary, the problem seems to be that since Firefox 44, running 32-bit version of Firefox on 64-bit Windows 7 seems to work only if you run it as Administrator.
Edit 3: now the problem has had an interesting twist to it. My bug report has been closed, as according to them now that Firefox has released a 64-bit version of the browser, I should have just switched to that and by continuing the use of 32-bit version of Firefox this is expected. Because currently the default upgrade path will not switch to 64-bit, this would lead to hangs on any user not heard of 64-bit version, which is probably a lot of people. You are expected to "just know" that you need to switch to another version manually by uninstalling and going directly to the site to download a 64-bit version.
Edit 4: bug re-opened, we're working on it.