I got the same message. I think it's due to the fact that my BF2.exe is cracked (so I don't have to use CD).
I guess I just have to reinstall everything.
Why would you need a cracked BF2.exe, because BF2 v1.5 (which FH2 has required to run since v2.2) no longer requires a CD in the drive?
Doh! I just assumed I had cracked it since I never use my CD (used to have it cracked before 1.5), I forgot that you don't need CD with 1.5.
Still odd though, since I never have tinkered with my FH2 folders.
I am reinstalling everything right now so hopefully it will be OK.