You installed a mod that search for that engine, but i guess the engine you installed is Harrison's version, and i expect him to have renamed the bmw v6 scripts because /care about compatibility so the game goes nuts everytime you select the car that should come with that engine.
This is the only thing i can think about.
Check your devil v6 folder and tell me if i'm supposing right or not.
With so much drama in the V-S-T, it's kinda hard being Bigg B-O-double-S-ninetythree