Crumplebottom is on the lot, she is at risk of being bitten, and that can corrupt core files in the game.
Note that once a Grand Vampire has bitten a playable Sim, any Sim, playable or not, who comes in contact with a Grand Vampire is at risk of being bitten, regardless of their relationship with the Grand Vampire. It may not be possible to build the relationship high enough for the bite neck interaction to become available, but at least get it high enough for the Grand Vampire to accept a phone call or invitation.
If one of them is going to appear, it may take a while, so make sure the Sims have high motives, or that they keep them up.
