A drawing may not open for several reasons. See below a list of recommended steps to follow if your drawing does not open. 

1. Make sure all available updates are installed. Go to the Help menu and click Check for updates. If updates were missing, install them and try to open the drawing again. If the drawing still does not open, proceed to step 2.                                                                         
   
   
2. Perform a Clean Start of CET. Go to Start -> Programs -> Configura -> Clean Start and click Clean Start. Once CET opens, try to open the drawing again. If the drawing still does not open, proceed to the next step.
                                                                                                            
3. Send in the drawing for review. A drawing that does not open will be given a message prompt for the drawing to be sent to support, allowing our support team to review the drawing.
   
   
4. While we review the drawing, you may try to open a backup of the drawing. To open a backup, either browse to the backup folder or place a check in the box Show Backups in the Recent Drawings area accessed from the File menu.
   You can also open them from the Load Drawing dialog as shown below.
   
   
   
5. If the backup opens, you may use this drawing; be sure to save the backup.
   
   
6. If none of the backups open, either wait for a response from our support team or contact us through our Help Center web page for a live chat session where we can remote in and help with the drawing.