Invalid Checksum Error is an error encountered in Scrap Mechanic when players trying to join someone’s game. This error is known to occur due to corrupted database files. Therefore, deleting the corrupted database file can often fix this issue for most people.
Fix 1: Delete interactive1.json file in database folder
To delete interactive1.json file, just follow the steps below:
- Before doing everything, close Scrap Mechanic and Steam.
- Open Windows explorer.
- Navigate to Scrap Mechanic installation folder (Default location: C:program files (x86)steamsteamappscommonscrap mechanic).
- Then move to data > Objects > Database > ShapeSets folder.
- You’ll see there is a file named “interactive1.json” inside that directory. Delete it.
- Launch Scrap Mechanic via Steam again.