Ok here goes. Game crashes (for me at least) if you are playing WoH and any alert comes through. Free gift, CvC, whatever.
Also, if you are in the middle of a round while CvC ends, game crashes. Just happened to me again earlier. For the third time today I was playing during the final moments of CvC and boom. Fortunately I was only on level 1 this time.
Yes, we are aware of the game having crashing issues in the middle of WoH, but we can't compensate you for the gold you lost at this time. This is done on a case by case basis. - TSB Customer Service