Hello!
I've search for this issue, but not found something relevant to it.
Sometimes, randomly, some folders gets its icons very small, which doesn't happen in File Explorer.
Yes, is still persist after Refresh or File - Exit Directory Opus and reopen.
I don't think the same folders keeps getting small. Folders appears to be randomly affected and I couldn't relate to something.
It affects local drives as well.
I almost can guarantee that File Explorer never got the small icons.
After some deep diggings, I have found another file manager which renders the small icons and also a weird black background on some folders:
I have jumped on a Virtual Workstation to make some tests as fresh installs and discovered that DOpus is the source of those black backgrounds rendered by Files App. If I use Windows tool Disk Cleanup to clear Thumbnails, all black backgrounds are gone and also size of affected icons get normal, but the black background come back after a new refresh with DOpus. I wonder if this thumbnail modification can also affect icon size on some folders.
The black folder background issue you're seeing in the other file manager is a very old issue in Windows that can affect anything that uses shell folder thumbnails.
It's nothing to do with Opus, and Opus has nothing to do with folder thumbnails in any other software.
It's a bug in Windows that has existed since Vista, where Microsoft's code doesn't handle the alpha channel properly and sometimes gets it so wrong that it renders the background black. You'll see it in File Explorer as well, from time to time, even on systems without any other file manager. It's a bug in the Windows shell that will affect anything that displays folder thumbnails generated by the shell.
I see! From my tests it seems that something was triggering the black background in Thumbnails Cache, since this effect persists on folders even after Windows restart and disappear only when using Disk Cleanup to clear Thumbnails. I will keep testing.
Yes, once one program causes Windows to generate a folder thumb, the thumb will then be cached and will continue to be displayed by that program and as well as any others, until something happens to invalidate the cache. (Either the cache being deleted entirely, or some aspect of the folder changing so that Windows generates the thumbnail again.) The cache lives on disk so it'll survive a reboot, too.
Every time Windows re-generates a new version of the folder thumbnail, there's a chance it'll get a black background (or lose the black background if it had it before). As far as I can tell, it's completely random, and it doesn't matter which application requests it either (they're all calling the same "get me a thumbnail for this folder/path" API at the end of the day).
