i have fs2004,it was playing beautifilly with add ons like 'airports 2' and 'hong kong'until i added on '737 ng'now it wont play at all.It says
this version of fs2004 detected is not compatible with this version of fsiupc
it is build 9.01.40901
you need the correct version of fs2004.
i thought i had the correct version until installing 737 ng