Originally Posted by
Fabo.sk
edit: Tried GVA and MIL, and got the error. Apparently it considers EU a single country... or it allows destinations in multiple countries, as long as there is a single origin.
The latter. It will allow destinations across multiple countries but not origins (and does not treat the EU as a single country either. Try with 'CDG, AMS' as departure, for instance, and see the result). Discussed
here. Rather a pain for me but so be it.