Use CAD Audit Command to manage Issues that are limited to a Single Drawing

If your drawing or CAD program seems to be behaving unpredictably, and you've determined the behavior is happening with just one drawing, use the _AUDIT command to check for errors, and, if necessary, repair them:

Type _AUDIT

Type "Y" when prompted to repair

The audit report will appear.  If issues were repaired, be sure to save, close and reopen the drawing right away

Take great care to perform audits before saving files intended to be used as templates or as AutoMap blocks.  

If you are unable to open a drawing, using the "Recover" command in the Drawing Utilities will trigger a drawing audit before opening the file.  This can save a lot of heartache.