If you needed to install gnome-themes-standard for use of Mint-Y without errors, for example. then you’ll notice you’ll also receive a new theme called Adwaita, that complains about window manager theme “Adwaita” missing.
Using the example for Adwaita mate-appearance-properties gives, I believe this is the “Proper” way to fix it, so do the following in order;
###The quick and dirty way when using it
- Select Adwaita theme
- Click on Customise
- Select the Window Border tab
- Select window border theme “TraditionalOk” and close
Previously I said to save as and delete original theme, but that doesn’t work, so keep as custom instead,
###Actually fixing it
I found that all I had to do to resolve the issue permanently was to do this;
sudo nano /usr/share/themes/Adwaita/index.theme
And change at the bottom where it says MetacityTheme to say TraditionalOk instead of Adwaita. I know why this works, I just do not know why Adwaita can’t use its own Metacity theme without issues, aside from what the kind people at #gnome@irc.freenode.net said about Adwaita previously relying on Mutter.
Feel free to tell me if I am doing it wrong and edit this to resolve the problem correctly.