Reply To: Error in Discovery while saving Workbench project

[Gary_S]

For the error: System.IO.IOException: Access to the path 'session_files' is denied.

This error most commonly ocurs when a Workbench project is being worked on while on a OneDrive location.
OneDrive sets the read-only attribute on the session_files folder, thus Workbench can no longer manipulate the folder. 
Copying a Project or archive to OneDrive for storage seems to work OK.

But I think you have two different issues here. 
In your case, it appears as if Discovery has crashed for some reason. 
Q: Does Discovery work reliably on your computer with other geometry?