I don’t know why your game crashed, IIRC .5 was fairly stable.
Solution: Download the nightly builds.
Despite what all the warnings are, the nightly builds are usually more stable. Really. AFAIK the bugs that are found in the official then they are fixed in the git version.
If it still crashes then you have technical difficulties. Also make sure you don’t use NPC’s, they are buggy. They could be the problem for ANY and EVERY bug if they are active.