Okay, im pretty angry. I couldent find a noticable problem juft from looking, so i went back to a backup i made. It was all working fine now and by adding back the information i established it definately wasnt desc buildings, desc mounts and desc rebel factions; though it wasnt likely to be them any way. I started adding back the units in groups and i seem to have found out what group caused it, except when i removed them again (both from desc unit and desc model battle) it still wasnt working
Im probably going to end up going to my backups of those folders again and trying to pinpoint exactly what causes it, real pain tho...