After spending some more time on this, I think it was a matter of syching up a number of new files created by the update to 2.6.1. I didn't have all of those checked in, because I didn't realize they were part of the update. So far, things are looking better.
Thanks

Sorry to not respond sooner: I am not able to share the entire folder structure due to IP (intellectual property) restrictions. I'll continue to work with it and see if I can get the problem to recur: Based on your comment, I'm suspecting that maybe during the upgrade process, something was checked in using an older version of the engine, then deployed to a newer version.or something like that.

I'll work with it on Monday and try to provide an update then.

We are seeing this same issue. Docker image: jsreport/jsreport:2.6.1-full..we recently upgraded to that from a significantly older version: jsreport/jsreport:2.0.0-full
Can you confirm how we can clean up/fix this?
Our error is with shortId A05ha9, although I think I've seen this with other ids as well.
grep -r A05ha9 ./
.//data/assets/config.json: "shortid": "A05ha9",
.//data/assets/global helpers.js/config.json: "shortid": "A05ha9"

Thanks,
Darren