[V 1.56 - Ground Combat] Mac release: The use of Vehicles causes consistent crashes

I reverted back to V 1.56 my most recent campaign iv just reached the month of January and up until this point i have encountered no issues. The latest ground mission i got i decided i would finally take the Scimitar tank i'd just built out for a test run. Unfortunately this mission can no longer be completed as using the the tank causes crashing consistently. Im not sure if this is the case for all vehicles and while i reloaded a previous save to avoid using the tank its effectively stopped my use of ground vehicles permanently. i understand the mac version is less stable that the PC version but this is limiting my options now for ground combat and could have been disastrous on an ironman save with no way to reload prior to the mission start.