`mscomctl.ocx` (part of the VB6 common controls) calls `HeapCreate(0x04000000,1,0)`, that flag is the old and undocumented `HEAP_SHARED`. `HEAP_CreateSystemHeap()` tries to map memory at `0x80000000`, this fails on Wow64 (and probably should for all 32-bit platforms for non-LAA EXEs).
As a workaround, map the memory anywhere if it fails at `0x80000000`.
I wasn't able to find much documentation about `HEAP_SHARED`, it dates back to Win9x and I guess Wine may have needed it for some native DLLs. It's not clear whether modern Windows really implements any shared heap functionality any more, every 'shared' heap created returns a different pointer (even in the same process). Maybe Wine should remove the functionality too?
-- v2: kernel32: Remove shared heap functionality. ntdll: Remove shared heap functionality.