Deleted any file with “forge” in the name (or moved it to the desktop as a backup).
Here’s a helpful, easy-to-follow story that explains what “mismatching forge file” means in Rainbow Six Siege , why it happens, and how to fix it. The Case of the Mismatching Forge File mismatching forge file rainbow six siege
When Rainbow Six Siege says “mismatching forge file,” don’t panic. It’s just a corrupted or leftover file that doesn’t match the official version. Delete it (or clear cache), verify your files, and you’ll be back in action within 10 minutes. Bonus tip from Alex: If you use an external hard drive or symlinks for Siege, move the game back to your main C: drive temporarily — mismatching forge errors sometimes happen due to drive permission delays. Deleted any file with “forge” in the name
Inside, Alex found a file named something like forge or .forge (sometimes in a data or cache folder). Exact name varies by update. It’s just a corrupted or leftover file that