hallo hjmoller, thanks for providing a crash id. unfortunately this crash is caused by the websense/forcepoint security software that is running on your device.

i presume that's in a corporate environment - please get in contact with your it department to make sure that websense is fully up to date, as it has the tendency to crash newly released firefox versions until they adapt accordingly.

another option would be to install an esr version of firefox: Old versions of Websense cause startup crashes in Firefox

thanks for the prompt reply. esr version 45.7.0 seems to work.

I've reported this to my IT departmet as well.