There seems to be various causes,
Getting stuck at 0% imo indicates the problem could be the devices and things that are always loaded, possibly HLOD related
and it could be from a spatially loaded thing within the loading range of the mem calc starting point… but that could possibly raise the percent before getting stuck… dunno, more a feeling than anything factual
If the new Validate Project in the Launch Session menu doesn’t indicate anything, I don’t know of a better way other than a systematic, time consuming search
Check in changes and make a snapshot, give it a description like “latest work - mem calc broke” then backtrack through your snapshots, find the most recent snapshot that will memory calculate.
The problem is in the content added after that, which is listed in the snapshot history of the next snapshot.
Go to that next snapshot and systematically delete stuff until it works, then zero in on the culprit(s)
Go to your latest work snapshot and take care of it.
If your snapshots are a bit sparse, its just more to search and test through, Check-in changes and make a snapshot, then start deleting groups of stuff and testing.
Start with the exotic stuff.
The last thing that was the issue for another poster recently was a Post Process Volume
It would be nice to compile a list of found issues