hello, could you provide your latest few submitted crash reports? please enter about:crashes into the location bar, copy the latest few report ids from there starting with bp- & paste them here into a forum reply. this will give us a better understanding what may be triggering those crashes.

List was posted in a new thread:

bp-f9280142-1f2b-40af-8804-0d76f2150330 3/30/2015 9:43 AM bp-f25d70d3-6f94-48cb-b267-6d5b52150330 3/30/2015 9:29 AM bp-503a6483-ea16-45ee-a980-c11982150330 3/30/2015 9:27 AM bp-ee18b50f-6845-43c6-8365-450042150330 3/30/2015 9:10 AM bp-9576f102-d865-48b0-b7c9-e6b282150330 3/30/2015 9:09 AM bp-afe7055d-b372-452a-a8d2-9383a2150330 3/30/2015 7:38 AM bp-b60ca998-c6f5-4b29-b867-bcd6c2150330 3/29/2015 9:54 PM 36e68411-3285-4e25-9ffb-0491a8d1ff62 3/29/2015 9:02 PM 22016955-cd9e-47c0-b592-c9bcc4ce5f46 3/29/2015 5:31 PM bp-a36d2548-1ee4-4295-a46e-c6e702150328 crashed while trying to get this info

I took a quick look at it seems Firefox is having problems allocating memory for itself. Either Windows has too many programs running and can't give Firefox more space -- crash reports show memory about 75% used -- or some component of Windows may have quietly crashed/malfunctioned and Windows needs to be shut down and restarted.

thank you - can you try the following and see if the problems continue: enter about:config into the firefox address bar (confirm the info message in case it shows up) & search for the preference named media.windows-media-foundation.use-dxva . double-click it and change its value to false and restart firefox for this to take effect.