What you were actually asking is how to be sure you are installing a theme meant for Plasma 6.(x). Correct?
There is no shortcut – You have to pay attention to the information provided with the theme before you install it.
If the theme information does not specifically state that it’s for Plasma 6 (or above) then simply do not install it. Instead, keep searching until you find a compatible theme that appeals to you.
There are not many Plasma 6 compatible themes in the wild. I would normally recommend using the default Breeze theme until random theme makers eventually update their themes, or create some specifically for Plasma 6.x.
One theme that you might like; and that’s known to be compatible;
is a theme called Carl:
Since there are old Themes for Plasma 5 version and themes which are to probably to new for Plasma 6.1 (if this is really the culprit for you issue…), i recommend to click on “show most recent first” and scroll a little bid down, then i found a Theme which was 4 month old like this one:
Which shows a creation date at middle february… which means there was just the Plasma 6 release… 02/2024 till 06/2024 should be good to install.
@soundofthunder Thank you so much, for like providing some themes. Really appreciate it!
I remember that some themes had Plasma 6 mentioned.
I’ll try using those!!!
Plasma usually works OOB with the default global theme.
Manjaro provides a branded version of the default Breeze theme - so it also works OOB.
Because themes is not just a bunch of colors and svgs - it is also QML (javascript templates) so some components may not work well if at all if it is too old or poorly maintained.
To see which global themes currently with KDE store and made specifically for Plasma 6
My preferred theme - is also a custom theme - and the current version of the greeter theme throws errors too. I have packaged it for my own use - so I still have a functional greeter.