After 5-7 uses of Calliope Sherman Barrage or British Howitzer Barrage (Creeping or just the plain one), these abilities stop fuctioning.This happens because a negative timer starts to count backwards(-1,-2...etc).I restarted missions without enabling instant abilities (Num key 8) but same happens.Other special abilities seem to work fine.This problem happens on both Mega trainers (2.501 and 2.502).