When loading ConceptStation, the window appears for a flash and then disappears. The application appears to be actively running according to the Task Manager but there is no application window on the screen.
The window position is saved in %LocalAppData%\Bentley\ConceptStationApp\DgnClientFx-LocalState.ecdb. As a solution, end the application process through the Task Manager, delete this ecdb (it will be regenerated on startup) and the application window should appear once the application is reloaded.
This has been addressed in future releases and a potential fix is to be implemented into the program.