Black Box has appeared in my Macbook Screen

Hiya,

An opaque black rectangle has appeared in the center of my mac screen and I am unable to remove it. It seems to mirror documents on my screen with a small delay and i can't seem to remove it.

I have gone onto several community pages and I have tried all given fixes to this problem, the most populer fix being "command + F5" which brings up voiceover options which are all turned off and are not part of the problem.

One notice is that I can drag apps that are in my hotbar into the black box and it deletes them from the desktop.

Any help would be fantastic,

Thank you.