Hello,

I just upgraded my Ubuntu 14.04 LTS branch server to Ubuntu 15.04 with a KDE based DE, this is specifically not the Kubuntu release.

Obviously, with any upgrade, I can understand some issues. But the problem with this is that KDE loads the desktop, but, it doesn't seem to load the rest of the desktop. I am not sure what is going on with this. If I go anywhere near the upper-left corner, I get a total gray screen on my desktop.

Below you can see the issues that happen. The first image, the environment is loading over VNC, second image is when the DE is fully loaded, the third image is when I hover the mouse in the upper-left corner. Plasma Version: 4:5.2.2-0ubuntu4

From my experience, Plasma5 is completely unusable via vnc. With default settings it's either completely broken as you experienced, or very sluggish. Even if you turn off all graphical effects and compositing, the response times don't improve to a level where it would be usable for anything productive. I have switched to lxqt for my remote sessions.