Assembly kit, more specifically bob, is missing a few files required to import new assets into the game:
we are missing a few rules.bob files, esp for the variantmodels folder
we are also missing the file for exporting an animation , this is called "rome_man_game_bone_table" in R2.
it is of type "BONE_TABLE_FILE"
if thats not enough info you can watch this long drawn out video discovering this all here:
ASAP add file