Description
There was an unexpected error during the Delete Field tool process. This can happen when a file is in use by another program, the file is a read-only data source, or the input has read-only permissions.
If the input is a dBASE file (or a shapefile), the dBASE file must contain at least one field. Attempting to delete all fields will result in this error.
Solution
Check whether the table is locked by another user, is read-only, or can support deleting fields. You can try using different output files. If that doesn't work, try closing the application and running the tool again.