I have two unraid machines both run slightly different everything and got this issue on both of them... The first time this happened I could not find anything online about it that was relevant after looking around (including trying to search this form) after 15 min so I blindingly updated, and it seemed to have fixed the issue.
I just logged into my other unraid machine and looked up the issue and found a lot better info this time around. My point is: did I miss the part of the unraid email newsletter, nonfiction or page on their site where they notified users? It does not matter if it's not on unraid devs of a result of the docker devs. The app store and docker are fundamental parts of their product that I would think most of their users bases relies on at best bugged and at worst not working (depending on use case)...