Hi Ard, I routinely build my app on U2004 and cross compile to Win64 (and others) without any problem. So, it 'should' work for you. Good move to do an simple app. But it did not work ? So, perhaps tell us a bit more about your build system ?
OS ?
FPC - probably 3.2.2 but from distro, source forge or source ?
Lazarus 3.0rc2, from source forge or source ?
You followed the cross compiler build recipe on the wiki ?
(Just the cross compile, I don't use Wine, but maybe someone else might be able to comment on that.)
Davo