It looks like a screen artifact of one of InDesign's tool panels is stuck in the interface.
I don't absolutely know if this will fix your issue, but it's worth a shot:
- Create a new document within InDesign. It shouldn't matter, but if things go awry, we're talking about corrupting a blank file rather than damaging a working file if things go horribly wrong. That's not likely, but why take the risk?
- If you're not already there, select the [Advanced] workspace on your system. This will confirm that the screen artifact is due to the switch of workspace, rather than the workspace interacting with content in your InDesign document(s). You likely know this, but it doesn't hurt to confirm the issue exists independent of a working file open on your system.
Open your Window pull-down menu. The screen capture at right shows what's open on mine when I selected the [Advanced] workspace. It only shows two panels "open", even though I have 13 tool panels parked in my Tool Dock on the right side of the application window.
- On my example, I only have two panels "open", my Control panel above the document window, and my Tools panel at the left side of that window. As I look at your screen capture, you have other panels open as well. Every panel that is visible onscreen and not docked in the Tool Dock should have a check mark, like the illustration at right. Turn all your panels off and on by clicking on the check marks to turn them off, then clicking on the now un-checked panels to turn them back on. Be sure to review all the sub-menus in the Window pull-down menu, because if your tool panel is inside one of those sub-menus, it won't show the appropriate panel-open check mark until you open the sub-menu that contains the panel.
If you're lucky, you might be able to recognize the errant panel before a trial-and-error search for your mystery hollowed tool panel. Hopefully checking off one of those open panels in the Window pull-down menu will make it disappear, which may be good news or bad news.
If by good fortune, you discover the errant panel that makes the artifact appear and can turn it off, try turning it back on again. Hopefully you'll see the full panel onscreen, rather than the empty artifact that's been driving you crazy. If you don't, and you get he empty artifact again instead of a functioning tool panel, come on back and let us know which one is causing trouble. We'll do our best to help you get it back.
Hope this helps you,
Randy