Sorry to hear about the crashes and thank you for the reports.

All 5 have a similar pattern: Firefox halts after code in qipcap.dll is invoked. I think this component is part of Websense Endpoint, which has caused instant startup crashes in the past few versions of Firefox. Websense's product support page indicates that there is a version 8.1.0 which supports Firefox 40-42.

http://www.websense.com/content/endpointproductmatrix.aspx

If you are running Websense/TRITON Endpoint could you check on whether you have that update yet?

If this is an unchangeable feature of your environment -- you can't update or disable Websense -- then you might want to try switching to the Extended Support Release version of Firefox (ESR). This is derived from Firefox 38 and while it will get security updates over the next several months, it will not get new features. Websense does say it supports Firefox 38.

If you decide to switch, here is how I suggest installing it:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(A) Download a fresh installer for Firefox 38.4.0esr from https://www.mozilla.org/firefox/organizations/all/ to a convenient location. (Scroll down to your preferred language.)

(B) Exit out of Firefox (if applicable).

(C) Rename the program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\Fx42

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\Fx42

(D) Run the installer you downloaded in (A). It should automatically connect to your existing settings.

Note: Some plugins may exist only in that old folder. If something essential is missing, look in these folders:

• \Fx42\Plugins
• \Fx42\browser\plugins

Thank you for quick response. Yes, I have installed Websense Endpoint on my workstation, version 8.1 Build 2231, Data Endpoint Policy Engine 8.0.1.129. It was updated today, and most probably caused this issue, so after all it does not seem to support FF 42... I cannot change it. Thanks again for suggestions.

Wow, they did it again! I think using the ESR release may work better for you. If you try that, please let us know if it works with the new release of Websense.

In the meantime I have found other people reporting the same, and our internal support team confirmed this is the issue with Websense provider. Until they release new fixed version we're allowed to get rid of this cr.... err piece of software. Problem resolved, thank you again for help.