Some prefabs crash the client when spawning. This was not happening before, might be related to a vu update or mapeditor changes. An example is familywagon prefab on XP3_Shield.
I suggest testing it in a sepparate mod to see if it works, then we can check differences or something.
prefab example: https://github.com/EmulatorNexus/Venice-EBX/blob/1b48533a42f9fce794b52b72e9e8bd33541e6b35/XP3/Objects/FamilyWagon_01_XP3/FamilyWagon_01_XP3.txt