Broken install on neon update

[meven]

You can try, it might be better:

Black screen with cursor after updating KDE Neon to Plasma 6

It’s a known issue. Try running the following in the teminal sudo apt autoremove sudo pkcon refresh sudo pkcon install libdecor-0-0 sudo pkcon install libsdl2-2.0-0 sudo pkcon install plasma-desktop sudo pkcon install plasma-desktop-data sudo reboot This is a proposed solution that you can find in reddit.