hi, thanks for providing a crash report. unfortunately this startup crash is caused by websense endpoint security software that is running on a device. please make sure that all its components are up-to-date. in case your computer is part of a managed enterprise environment, please get in contact with your it department about this issue again. more information is available in bug 1181091.

in a larger enterprise using the extended support release (esr) version of firefox, which receives security updates but feature updates only once every 10 months, might also be a better option compatibility-wise: https://www.mozilla.org/en-US/firefox/organizations/faq/

hi again, could you try if the build from here works again and addresses the startup crash?: https://archive.mozilla.org/pub/firefox/candidates/48.0.2-candidates/build1/win32/en-US/