hi jhenneike, can you please try the following and see if that works: enter about:config into the firefox address bar (confirm the info message in case it shows up) & search for the preference named browser.tabs.remote.autostart.2. double-click it and change its value to false.

Thank you philipp. My firefox now loads normally again. Is this a new default setting? or what could have triggered this? I ask because I have several users at my company that have this same behavior, but no everyone is affected...

this is the setting that controls the new multiprocess-architecture in firefox ("e10s"): https://blog.mozilla.org/futurereleases/2016/08/02/whats-next-for-multi-process-firefox/ in firefox 50, e10s was enabled for more users on firefox release (everyone with compatible addons), so that's probably the reason why you started seeing it after the last update...

could you point your it department to chime in at bug https://bugzilla.mozilla.org/show_bug.cgi?id=1319055 which was filed just today as well...

I will pass the request on to our IT folks.

Thanks again.