Created attachment 108331 [details] Screenshot ¯\_(ツ)_/¯
This was fixed a while ago, it was an issue with the cgcicon.knsrc file that we actually weren't using anyway. Make sure you have the last version of plasma 5.11 (kde-gtk-config) and you won't be seeing this message.
Hello, I'm running plasma 5.11.2 on KDE neon user edition and I am still seeing this message. Thanks
Check if you have /etc/xdg/cgcicon.knsrc. Apt doesn't clean up files in /etc so you will have to remove it by hand.
Thanks! Also had to remove kaddressbook.knsrc but now no more error message :)