In a 100% vanilla installation of RimWorld, you will almost never see this error. If you do, it usually indicates a corrupted game cache. However, for the other 99.9% of users, this is a or a Broken Def .
The "ERR Site Label Detected New" error in RimWorld can be frustrating, but it's usually solvable with some troubleshooting. By following the solutions outlined in this article, you should be able to fix the error and get back to building and managing your colony. rimworld err site label detected new