Suddenly error in Unity after using tilemaps

Hi, I get this error when I worked on a Project. Tested around a bit and it seems the error only appears if I DON’t have a tilemap in the scene. In every scene with a tilemap, the error does not appear. As soon as I delete the tilemap the error appears. So far it seems it does not affect anything I did since everything else works just as before, as far as I can tell. Do I have to worry and if yes, how do I fix it?
grafik