Ok, I've got an update for you! I noticed all the problematic fabricator machines were filled with little parts (to create something). As soon as I'm in Live mode I can visit the place with a sim and remove those little parts. I switch into buy/build mode and CAN remove the fabricator machine. Still this has to be fixed because of an endless loading circle loop whenever I try to bulldoze the lot.
Maybe the lot got an update? I contacted the creator about it but didn't check again. But I'm pretty sure it isn't about specific lots but about the fabricator and included part tiles to the object.
