Click the Application button, and choose Drawing Utilities Audit.
At the Fix Any Errors Detected? prompt, enter y or n.
AUDIT places all objects with errors in the Previous selection set for easy access. The output from the audit is written to an audit log (ADT) file if the AUDITCTL system variable is set to 1 (On).
Note: If the drawing contains errors that AUDIT cannot fix, try using RECOVER. RECOVER repairs any specified DWG file that is not the current drawing file.