Most of the library icons have been custom set using the windows properties dialog
They are displaying as directory opus folder thumbnails instead of the custom icon that has been set, I have other custom icons in other folders that have no problem displaying as the custom folder icon.
The thumbnail settings are all in order I believe
In my experience, if I experience problems like this I usually just exit dopus (not close) and reopen it. And if the first step doesn't work, just rebuild the icon cache in windows and clear the icon cache in dopus.
it's not an icon cache problem, for some reason the library folder icons are displaying as directory opus folder thumbnails even though 'exclude folders with custom icons' is checked.
A point of interest since upgrading to V13 beta I have set a global hot-key combo to close DO properly and restart.