Hi Steve, Sorry you are having problems. Version 15 should be ok, I and many others have been using it for a few weeks. (it is available to test before it is officially released ) I suspect what is happening with you is that something is blocking Firefox. If it was actually crashing it should attempt to send crash reports. Security related software may not like the fact that some new program is trying to become the default browser. You will need to check security and firewall settings. See * [[Configure firewalls so that Firefox can access the Internet]] *[[Firefox won't start - find solutions]] ------- If you are actually having crashes then see * [[Firefox crashes - Troubleshoot, prevent and get help fixing crashes]] and it may help if you send a screenshot * [[How do I create a screenshot of my problem?]] Have a look at the linked articles and your security settings, and then please post back with how you get on.