Firefox hangs upon pressing a Browse... button in a file upload form
Firefox consistently hangs when you press the Browse... button on a form to upload a file.
This affects one single user account. The problem occurs even in new firefox profiles. Other users on this computer are not affected.
Wšě wotmołwy (3)
The hang occurs also in firefox safe mode.
For us this was fixed by backing up then deleting the user's windows account profile. The problem disappeared in a new windows account profile so this was likely a bad or corrupted registry setting, but also possibly something in the %userprofile% files themselves.
It was actually possible to restore the firefox profile and use it without any errors.
Maybe a problem with the MRU keys in the Windows registry.
You can try to delete the MRU (Most Recently Used) ComDlg32 registry keys with the regedit.exe program.
Navigate to: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32
Delete the subkeys (LastVisitedMRU and OpenSaveMRU).
Be careful with editing the registry as there is no Undo possible: all changes are applied immediately.
You can export key(s) before making changes.