Same here, 5.2, a wall of:
LogPackageName: Warning: DoesPackageExist called on PackageName that will always return false. Reason: Input ‘’ was empty.
as the game starts (after begin play apparently).
Even with a completely blank project, empty level, no world partition.
I’ve also noticed that in any populated project (brand new template or converted old project) the warning also appears while scrolling the outliner.