macOS Catalina external displays are black but I can move the cursor on them I just updated to macOS Catalina. I have two external displays that only show a black background. I can see the cursor moving on them, but no windows or dock. If I try to move windows from my MacBook Pro on the screens, I only see the cursor on the external display. 

Any ideas on how I might resolve this??
I just had the same problem. In order to fix this, go to System Preferences->Security&amp;Privacy->Privacy, scroll down the left list until you find ScreenRecording and make sure DisplayLinkUserAgent is checked. After you check it, restart your machine and everything should be ok.