Sorry, Build HLODs, is using the Build HLODs from the Build menu up top, it essentially takes all props that are “included in the HLOD” and builds a bunch of lower quality meshes out of them.
These HLODs meshes replace everything off in the distance, outside the loading range, so any Spatially Loaded props will unload from memory and we see the HLOD instead.
It will have a HLOD Layer, but yes, not the issue because the World Streaming test failed
Custom Content is usually the culprit, and there seems to always be a lack of information about it in the message log. Any other red or yellow stuff in any message log categories ?
I have no experience with skeletal meshes, but I know there is a set polygon limit to UEFN, I’m unsure of what it is but I remember it being mentioned in a post a while back.
Delete them and check, then revert to your last snapshot and try something else.
It was either something you added or the update changed something that’s already there.
Do you remember what you added/changed since your last successful launch ?