The IIS Manager UI has a lot of capabilities, one of which is the ability to download new UI modules from a server when connecting remotely. This means I can open up any IIS Manager, connect to a server and get all the UI modules you need. Seems magical.
Well, where do those "UI modules" actually go? You will find them here:
(The 18.104.22.168 version will change over time ... such as 22.214.171.124 and 126.96.36.199, etc.)
If you need to clear them out, this is the place to go ... not easy to find. I could not find an article that describes how this works, but if I find one, I'll post it here.