Thank you for that tip, Neil. I did some research, found the folder the caches are stored in, deleted the files there and even reset the icon and thumbnail caches via Winaero Tweaker. However, even after multiple clearings of the assorted icon caches and reboots, I'm still getting a black square if the program is not running... I'm kinda at a loss.
I did notice this: If I pin the icon to the taskbar from the programs list in Start11's start menu, it shows as an icon. However, when I click that icon, it shows a second running icon, as if they're two separate programs. Clicking on the taskbar icon of the running app and pinning it causes the black icon when it's not running. Does that make sense?
In this particular instance, these are the steps to reproduce on my system:
• Click on Start, find the program in the alphabetical programs list, right-click > more > pin to taskbar
• Activate the program either by clicking on the icon on the taskbar or in the start menu > a second running icon appears
• Right-click on second icon > pin to taskbar
• Close the program == First pinned copy's icon correct, second pinned copy's icon a black square.
I will note that for all other icons, I can right-click > right-click again on the program name > select properties. There is no properties option for the black icon.
I don't know if this is related or a separate issue, but I did notice that if I've got the black icon pinned, say, four from the right end of the icon row and I move another icon near it, the black icon the icon to its right move in sync, as if they're one icon -- I cannot place the icon I'm moving between the two. However, I can later move the black icon by itself. This doesn't even begin to make sense to me. I just checked and found there are five other pairs of icons this is happening with, but only this one is visually wrong.
Thanks for your suggestions!
Kehvan