Hi @hb903
Thanks for posting on our forum! 
The cause of this error message is due to the fact that the Windows Error Reporting system has determined that the application is no longer responding and presents the alert.
Please, follow these steps and retest the behavior afterward:
- Close all Revit sessions on your computer
- Go to Windows > Start > Search field and type %temp%
- Hit Enter
- Clear all instances in the Windows Temp folder
- Skip all instances Windows reports to be in use
If clearing the Temp folder does not clear the issue, there are two more approaches to track down the cause of this error:
- Check the Revit journal file to see if it shows a problem prior to the error.
If the steps above do not lead to a solution, cleanly uninstall and then reinstall Revit
Please select the Accept as Solution button if my post solves your issue or answers your question. Kudos welcome!
Regards,