That does not sound right. Mine has been rock solid since Wednesday night, and I know Windows 10 insider preview on my 640 never crashed the whole Phone. Especially since it crashed while you are not using it, that is not a good sign. You may have a hardware issue with your phone. On the messages, when I did some factory resets to install versions of the insider Windows 10 versions, sometimes it took a while for all of the text messages to migrate over to my phone, but they eventually all came over. You may want to talk to Microsoft to see if it needs to be replaced.
11-27-2015 10:33 AM