Units Self Destructing!
Please observe with linked replay that about time reference 6:55 there are reinforcement units travelling north and as they reach the ramp up to the plateau where the centre of the map generator is they each self-destruct! If this is a bug then it is a very frustrating one.
https://www.dropbox.com/s/npi21veege46fak/Urich%20%287%29.AshesReplay?dl=0