Howdy Dicho

Missions run off the .res instead of the .mis file now, so the old missions are obsolete unless they've been updated (very few).
Here's the one's I know work fine right now:
Rune's Rumble 1 & 2
NOE Strike(fun one by Stixx)
Bloody Gulch Redux
Palm Sunday Massacre (haven't tried it yet but he says it's fine)
To update an old mission, open it up in the M.E. and hit File->Build Res Library. This will automatically place the .res file in your MISSRES folder. Don't do that with any of my old ones though, because all the audio stuff I used makes it hell to update, unless you want to move umpteen million files around. If it's a "basic" mission with no audio files or anything, it's easy to update it using the method described.