Try loading it in the mission editor and see if something is no longer working.
You didn't say which version of RA you are running, so I'm guessing you mean RA 1.44? I have RA 1.44 loaded but I have been using 1.43. I have noticed that 1.44 has made some large changes in the platform database which causes some of the old missions to fail, but I really haven't played around with 1.44 a lot.