Quoted from adam12hicks:
No luck on terminal window. No alt-tab action. Only a black screen with a cursor. I can right click and get to display settings, then all settings, then see most of the settings dialog window for sound, network, etc. but never any way to execute a terminal command or file explorer / browser. It's like application execution is completely disabled. I wonder if this was changed at some point on the machine to prevent any modification?
No idea why that doesn't work. Try right-clicking anywhere on the black screen and you should see a new folder option. Select that and you should see the folder on the screen and be able to double-click on it to open the file manager.
FYI - I'm able to get to the file manager at least 2 different ways with a keyboard connected. I had to get rid of that Ubuntu crash message yesterday.