Ubuntu: Nvidia Applet disappeared after switching to Intel Graphics

Question

I am using Ubuntu 20.04 Mate. And I had some trouble getting my external Display to work via HDMI, therefor I tried switching from nvidia graphics to intel graphics using the applet in my Desktop Panel. Now I can't switch back to Nvidia since the Applet Icon disappeared. I tried checking the Nvidia Settings, but it shows just an empty window. The Nvidia Card worked perfectly till now. How can I reactivate it?

Answer 1

I resolved this by reinstalling lightdm

sudo apt-get install --reinstall lightdm ubuntu-desktop