infoRouter uses warehouse paths to store document contents and other meta files. When a document content storage location in a warehouse is inaccessible, or a part (or all) of the path has been deleted, this error will occur.
Another possibility is inconsistency between the database and the warehouse information.
Restoring from unmatching database and warehouse backup sets will also cause this problem.
Restore the warehouse path from the latest backup.
If you think the warehouse path (example P231312) is corrupted or missing you may restore the specific warehouse path from the latest backup.
If this problem occurs right after a warehouse migration or restore operation make sure you restored or copied matching warehouse and database backups.