Dear Dutch, FWH does not impose any limit on that, so I guess that you are reaching the limit of your Win32 app default HEAP. You may try to increase the heap using the linker flag /HEAP when linking the EXE: /HEAP: 0x10000, 0x1000 Please try to increase those values. https://www.labri.fr/perso/betrema/winnt/heapmm.html ...