Because he had the borked version that left invisible tankers he now has the save game with invisible entities and the way to remove them is to remove the mod, save the game then put back the mod but that will remove all his tankers from the game so the only other solution is to move the cursor ove...

unfortunately not, it still has invisible boxes on the spots of my stations. I still need to rotate or remove the pumps to get oil flowing, each train.