Well, not sure where this dark UI overlay comes from. MAybe it was a problem due to LibAsync's update which destroyed IIfA then (for some houers).
I think we did not experience this as we had removed LibStub from the versions of IIfA, we are using locally, since months already
I cannot say anyhting about your approach of updating addons. Minion just works fine for me so I do not see any reason in doing it by other ways, or totally manually.
Whatever could happen with your 3rd party tool: We cannot say anything about it, so your assumption "That leads me to believe that something could be self corrupting itself?" will just be unanswered from my side. I doubt it though IF you use Minion OR manually update the addons.
IF your RAM fis broken-> This would be one reason how files could become damage after/during downloads
But back to the topic: in the end I still wonder where IIfA could or would add some textures to the UI, or any overlay.
Is it still happening now as LibAsync and IIfA were updated?
If so you should still do a test with ONLY IIfA, and then add the other addons you have had enabeld as the error happened.
And then find out which combination of addons leads to the UI overlay.
It's definately not happening with IIfA and my addons.
@Sharlikran
The list looks like a name of addon -> link list (scroll lto the right). It's not the live/AddOns folder!
Maybe for his 3rd party download tool, or internal use.