Completely slipped my mind to report this on the forum during the 1.86 test builds sorry though did mention is in the skype chat a few times.
So reporting it now in case i forget again and for someone to have a look into this.

Happens on AOD's, if there's already units at a spawn position and a script tries to spawn a Team which has a Troop crawler in it
When the team spawns it causes a serious error.
Only happens with crawlers and none of the other Propaganda units with and without the subliminal messaging upgrade researched.