Talk about Severance Blade of Darkness modifications and maps here. No tips or tech support questions please, use the forum above. Note that the game is rated 18 so some content may be unsuitable for younger readers.
You may have accidently corrupted a BOD file. Try removing the last files you added and see if it works. If it does, then add one BOD at a time until you get the error again, and then remake the corrupted BOD from the original.