HI @SubtoC4CTUS ,
In the log is the line
Error: ProjectSizeRequest: : CancelFlow for f45e4138-44ec-97f3-9c76-3590108e41c5 - Content (re)cook error errors. com. epicgames. cookplugin. assetvalidationerror.
assetvalidationerror = asset validation error
Therefore use the
Validation and Fix-Up Tool | Unreal Editor for Fortnite Documentation | Epic Developer Community
Look for changed/failed assets in the logs
Also, look at this thread to determine which asset is causing the problem
Asset Validation Issues - Issues and Bug Reporting / UEFN Validation
This is trying to find the project size
Try and use UEFN Memory calculator , before trying to log the session