I added more information on this issue in the related post
Undo update - Development / Platform & Builds - Epic Developer Community Forums (unrealengine.com)
I found a workaround, described in that post.
UPDATE:
If I open the level with one or two regions loaded (including the generated PCG’s) there is nothing wrong - it takes about 30 mintes (25 or so at 84%). I can load other regions so I have all 4 regions loaded but run into the unusable viewport. Closed the project yesterday with all regions loaded and all PCG’s generated.
Today I opened the level again and again, Unreal crashed. After restart in the default (standard) level I looked at the folder that holds my spline-based PCG’s and found that all my data-assets are no longer covered by their icon:
This is the log of the latest crash:
Oasis-backup-2024.10.02-13.46.13.log (316.7 KB)
but when I rename such a file, the class is corrected.
My suspicion is that the spline- and data-asset based PCG’s are key to this problem, because if I remove them from my project, I can load all 4 regions without a problem. A few is not a problem but I have about 8 in each regions, each covering a large area.
I will have to postpone further work on this project, this blocks me completely; I need all four regions loaded for the next step I had in mind, until this is solved.