Hi,
We had a hiccup at the P4 level when we integrated all the 5.6.1 fixes from Dev5.6 to Rel5.6. Three files from UBA didn’t make it and we only discovered it after the hotfix was live. The problem was addressed with https://github.com/EpicGames/UnrealEngine/commit/d9ebb27bc32a04a62d87f4a32cbe65e9eb3607ff
The Release branch is a mapping on the last release so it stops at the wrong commit on the 5.6 branch. The 5.6.1 tag and the release are also missing the files.
The binaries are the correct one so it’s only a problem when trying to compile it.
Sorry for the trouble,
Martin