I am using a Samsung Galaxy s5 with Android v5.0 (had problem with previous Android version too). I have the standard default installation of Firefox with no additional addons/plugins/etc. I have the last Android version of Flash player installed from the Adobe archive. Flash content works without problems using other browsers and appears to be working with Firefox too, e.g. Flash content is displaying correctly and interaction is working. I only mention here as it is a the only non-standard thing I can think of. _____ Problem: Firefox works fine for usually between 0mins to 60mins. It will then randomly stop responding. This can happen on any page including ones which had worked fine a few minutes previously and does not seem restricted to any particular site. All buttons and controls on the web page stop responding - no actions performed, no text/links highlighted, no button press animations, etc. I am still able to zoom in/out on the current page and scroll around it. The Firefox menu button (top right) works but the previous/next page & refresh buttons etc do nothing. When I rotate my phone it keeps the original width/height so ~half the page is blank. I can still move the page around on screen and see what was under the blank area on the visible part. Once it has stopped responding if I leave phone on same screen sometimes it can sit for hours with no action or crash message. Normally it will give a "Firefox has stopped responding" message after a few minutes or very rarely it will start working again. If I just leave it and switch to another app I will eventually get the stopped error message after around 5-10 minutes. ______ I have tried removing and reinstalling the app & resetting phone to factory settings with no improvement. I have a reliable data connection and have problem both via wifi and using direct connection (on Three UK network). Any help would be appreciated.