I noticed some people are having the same trouble I am having.
Before I updated to Entrenchment Beta 3, I uninstalled both the original vanilla Sins and the previous 2.5 Entrenchment beta.  I also went and deleted all old Entrenchment stuffs (saves, custom maps, etc). 
After I downloaded the game again and installed the new version of Entrenchment, every game I played minidumps quite quickly.  I never had this problem with 2.5 beta with my usual settings, and the RAM usage hits 1.6 GB on a start up of a medium sized game.
I thought I had another installation problem and verifed Entrenchment.  Impulse told me Entrenchment had installed incorrectly, so I installed the ~100k update.   But now, Entrenchment refuses to believe I deleted all my old beta files (everything is cleared completely) so I can't play the beta without redownloading the entire game.
Is there a fix to this?  Am I missing something?  I had a installation problem with the previous 2.5 beta, but Verify Installation fixed that one.  Now verify installation breaks the game.