There is a known issue with Forcepoint/Websense Endpoint (enterprise antivirus software) that causes crashing in Firefox. We are working with them to fix the problem. In the meantime, here’s what you can do to continue using Firefox.
Option 1
Old Forcepoint/Websense Endpoint versions may lead Firefox to crash on startup. Please get in contact with Forcepoint/Websense technical support to obtain the latest available version for your security product to fix the issue, or work with your IT administrator to upgrade according to Forcepoint/Websense documentation about supported versions.
Option 2
Users affected by this crash can also try switching to the Extended Support Release (ESR) version of Firefox that's available under https://www.mozilla.org/en-US/firefox/organizations/.