Hi there,
yesterday I've updated Neon KDE with available updates, everything worked until computer was rebooted. After update Plank is running but is not visible. I've tried using "plank --preferences" command and preferences windows pops up, but nothing is displayed choosing any of available themes.

Also Firefox Menu and Bookmarks is not showing up.

Both, Plank and Firefox are running, I can click to select a Plank application an it runs, but always without seeing what you are clicking.

Rebooting both service or computer does not solve problem. I've downloaded last Firefox version and problem still persists. For example Chrome works fine.

Regards

It doesn't sound like the Plank issue and the Firefox issue are related.

For Firefox issue: https://support.mozilla.org/en-US/kb/customize-firefox-controls-buttons-and-toolbars

For Plank issue, kill all running plank processes and start it from the command line in a konsole window. Do you see errors or different behaviour? There could be several reasons why plank is hidden. Look at the configuration options in its preferences: https://elementaryos.stackexchange.com/questions/1966/keep-plank-unhidden-and-maximize-windows-to-plank-like-in-os-x

First of all, many thanks jchoksi for your reply.
Finally after many days looking for a solution everything works fine again with a simple configuration change:

KDE System Settings -> Display and Monitor -> Compositor (left side) -> set "Rendering Backend" to XRender>

Previous value I had was OpenGL 3.1

Solution was found at: https://www.reddit.com/r/kde/comments/6 ... _kde_neon/