I use Folder Painter Folder Painter v1.3 to change the colors and icons of my folders to make them easier to identify. However since I updated to 13.11 on Friday through 13.11.3 today it picks random icons rather than the ones I chose. It still works fine in Windows Explorer.
If you reinstall 13.11 does it work again? I can't think of any changes we've made that recently to how Opus asks Windows for folder icons.