Prompt boxes are "invisible". When a prompt is active, a click gives the bonk/error noise, but the prompt box can not be seen. For example, when you select save, and there are unsaved changes, I get this noise response. I assume there is a prompt box asking if I want to save changes, or something, before saving. The "invisible prompt" can not be exited. For example, when I click the return button to blindly agree to what ever the prompt is, it just continues to make noise. All keyboard input only results in the prompt noise. Only option is to force-quit Photoshop (losing all work); or pressing esc key. When esc key is pressed, there is a brief flash of the previously invisible prompt box which then disappears (too quick to read). You can now save changes, and save your work, as long as you do NOTHING to trigger a prompt.