List Component Suddenly Not Displaying

[Velma]

My application in Production (Vancouver) (application version stable there for at least six months). The List component suddenly stopped displaying a couple of weeks ago. (I was on vacation, not sure exactly when). There are two List components in my application, both are just acting like they don't exist. The data is fine. And all other data accesses (Simple List, List Nav, GraphQL data resources, transformations to the calendar, Platform) are fine. So it's hard to see it as anything other than specifically a List component issue. In my stack, my Dev and QA are still fine so far, UAT and Prod have this breakage. (I guess I can apply myself harder, but I can't even figure out if it's downloading the data and not showing or not downloading the data--but the component is not showing anything, not showing the frame as it would if getting back zero records.) My internal support says all instances are on the same patch versions. He put in a ticket to ServiceNow support and I participated in a call with them--initial take, no idea--hopefully they'll figure out something. (Walked my support through creating a new experience in my scope and then in Global on the UAT instance, and List component just not working.) Anybody else seen this? Anybody have a clue? (There was a similar behavior I think in 2022 KB1402436, although not the same issue. Tried their fix anyway, but no go.)

[Velma · Accepted solution]

So it took five weeks or so, but ServiceNow Support figured this out and my internal admins implemented the fix for me. Documenting in case someone else runs into this. The List component data is bundled in a batch. Abruptly that batch download started failing for my two list component pages in my application in Production--and for any other List component pages in any scope or global. (That far I could get even with my limited access.) So (and this part is not direct because layers, limited access)--that batch was downloading every UI Script in the instance!!!! and there were a lot of UI Script's. So someone added a few more and the batches started bombing. The fix is to add the table names to "glide.ui.list.batching.exclusion.list". Bingo, hard refresh and the lists started showing again. This is Vancouver. The story was this will be fixed in Washington, DC.