I've finally been able to get to my PC to retry this in WinUAE with the increased stack size as suggested but it's failing in the same way as on my real A1200.
Is there a simple way to be able to tell what filesystem my emulated hard drives are configured as in WinUAE please?
lantus360 - can I ask where you obtained your version of the Shareware .wad file please? Perhaps the one I have is incompatible with your Amiga version for some reason but OK with the old PC version?!?!?