RebuildSimulation set as True and amalgamation can't be together :)
When PropertyBool RebuildSimulation is set to True
PropertyBool IsAmalgamated is set to True
then we get: Error - detected 34 fields with PropertyBool IsAmalgamated 1 but
only 68 in Amalgamation MiceModules
Error at BTFieldConstructor()
This error goes away as soon as we set the RebuildSimulation to False (and amalgamation to True) or when we set the RebuildSimulation to True (but then amalgamation must be set to faulse).