Hi Bas,
Appears to be working fine on Win11:
though as you can see leaving out the .yml extension results in a funky message. Please note that I haven't tried to actually run the vhd on PCem or MiSTer.
output alleycat.vhd:
MD5 9cb6b2bb9d315726a4b6ab7de5a401a1
SHA 0fffca953b3243063b4059c0cd09a35ad4ba173f
Regards,
Ronald