What device are you using? Have you check to make sure you're fully up to date yet?

Always update when possible.  This is On my 1+ (mobile).  3 times in the last 10 minutes has crashed.  It just Started  with this crazy frequency since update 5.00.  I Try not to complain too much but this is crazy, if I'm running dungeons it's like 20 energy per reload (or 50 during 2X).  So it's straight up stolen half of a refill in the past 10 mins.  Really we shouldn't be getting charged for battles we don't get the chance to start.  It's just never been enough to complain about In the past.