To create a maplist, i decided to build the same system Epic uses for UnrealTournament. Extending WorldSettings with a new property-object which holds summary information and at runtime, extract/load that specific summary object from a map. However, i noticed things are quite different in packaged games.
Here is the code from UT (since i can’t share project source atm):
The asset specific stuff had to be changed since AssetRegistry is a bit different in 4.17.2 compared to the version UT uses. But from the part on after it, its the same. Right now, i have 2 of our maps loaded in editor and set summary info. This means these 2 maps use the new worldsettings and summary-object. Several other maps don’t(yet). From PIE (or Standalone from editor) Linker->FindImportClassAndPackage reports true on the 2 maps i have modified and false on the other maps not using the new stuff. That seems right. The rest of the code then runs like a charm. In a packaged build, this goes bonkers. Linker->FindImportClassAndPackage always reports true and Linker->Preload will always fail with an assertion. Even on those 2 maps i modified. The assertion is:
Assertion failed: InPos >= 0 && InPos <= TotalSizeOrMaxInt64IfNotReady() [File:D:\Build++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading.cpp] [Line: 7183]
However i see no reason why this check fails only in packaged builds