Ya, its not liking this. So I did a simple set of tests. 1 Directory with 2 Sub-Directories (Planet\Landmass1\Compound.umap & Planet\Landmass2\Beach.umap) Each with a .umap contained within each Landmass directory.
I set up the OnActorOverlap trigger to move the player from the Compound.umap to the Beach.umap … Its crashed each time.
Here is my crash log
=============================================
!Id:b61d3db364682e5c24a0eb59427cbdc5
Unknown exception - code 00000001 (first/second chance not available)
Assertion failed: LoadSucces [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.4\Engine\Source\Runtime\Engine\Private\UnrealEngine.cpp] [Line: 7745]
KERNELBASE + 37901 bytes
UE4Editor_Core + 3095148 bytes
UE4Editor_Core + 1661722 bytes
UE4Editor_Core + 1541808 bytes
UE4Editor_Engine + 8827698 bytes
UE4Editor_Engine + 9122557 bytes
UE4Editor_UnrealEd + 1812794 bytes
UE4Editor_UnrealEd + 5925286 bytes
UE4Editor!FEngineLoop::Tick() + 3294 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.4\engine\source\runtime\launch\private\launchengineloop.cpp:2098]
UE4Editor!GuardedMain() + 476 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.4\engine\source\runtime\launch\private\launch.cpp:133]
UE4Editor!GuardedMainWrapper() + 26 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.4\engine\source\runtime\launch\private\windows\launchwindows.cpp:125]
UE4Editor!WinMain() + 249 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.4\engine\source\runtime\launch\private\windows\launchwindows.cpp:201]
UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]