I keep getting this error in fire fox 14 and hoped it would go away in 15 but is continuing. i have tried to repair the install and uninstalling and re-installing with no joy. the error message reads.
Microsoft Visual C++ Runtime library Assertion Failed!
Program:... File: common\npn_gate.cpp Line: 267
You can do a check for problems with plugins.
You did try to disable all plugins (Tools > Add-ons > Plugins)?
Try to create a new profile as a test to check if your current profile is causing the problems.
See "Creating a profile":
There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" in case there are still problems.
If the new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files.
You can also try to reset Firefox:
Try to do a clean reinstall and delete the Firefox program folder (C:\Program Files\Mozilla Firefox\) before reinstalling a fresh copy of Firefox.
Download a fresh Firefox copy and save the file to the desktop.
Uninstall your current Firefox version, if possible, to cleanup the Windows registry and settings in security software.
Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.
Your bookmarks and other profile data are stored in the Firefox Profile Folder and won't be affected by an uninstall and (re)install, but make sure that "remove personal data" is NOT selected when you uninstall Firefox.
Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that works.