While bugs are possible (and I can point to several, including mine), KoLmafia daily builds are likely to do a better job keeping up with KoL changes. Anything introduced by KoL since KoLmafia 20.7 (July 2020) is not going to be there. Especially at Crimbo time, there are KoL changes that will affect play.It is idiomatic around here that "latest build" and "up to date" refer to the builds available from https://ci.kolmafia.us/ and not what is available at SourceForge.
There is a mechanism for script writers to indicate that a particular daily build (or newer) is required, the since directive. As noted above zarqon failed to update that when a zlib update was pushed, but that error has since been corrected.
Users who wish to protect themselves from similar oversights by script authors tend to do so by always using the "latest build" as defined above. The days when the daily builds were buggy and unstable are long gone and since 5 months have passed since the SourceForge build was last updated the commitment to keeping SourceForge up to date might be wavering.
Your steps to try and resolve the issue were perfectly reasonable although ultimately incorrect
We've done some work to make releases more efficient so we can get on a better cadence, but the process is still a bottleneck.
And sourceforge has a number of things that are out of date on it, especially in the documentation. It still lists Java 1.5 as the required version.