Ok i'm having some trouble with FRED as the title suggests..
First off, I'm using FS Open and It is a pretty ship heavy mission, but before you make presumptions here's the probem.
I made a mission in fred. It worked just fine although it had too many ships in it (slowed my comp, shut down FS2) so I got rid of some unnesacsary cargo containers and freighters. Play it again, its going fine.
Then I go to do my debreifing and all. I do the debreifing and finish put some finishing touches on it and I'm done. I go to test, It works fine but I wasn't paying attention (damn soda) and I got hit by a Hecate on it's way out (shut up.) I realised there were a few problems with message times and I noticed that Delta wing came in when they weren't supposed to. They are supposed to come in when One of the ships turns traitor.
Ok, so I get back onto FREDOpen and go to make the changes. Easy, I adjust the message length, notice that my Hecate wasn't talking when it was supposed to because I accidentally had it on the wrong ship or something, fix that. Everything looks good right?
Well ok, I start up Freespace, select the mission and it locks up on the mission selection screen. Doesn't even go to the loading bar. The music cuts off and its just the message screen.
I finnaly broke out of it and got into windows and tried it again.. same thing cept I had to restart. after restarting my comp, I tested another mission of mine. Worked perfectly. I figured hopefully the problem fixed itself (

)
Come back, try it again, Locks up. So yeah, that's my A-1 Supar detailed problem.. who wants to step up and help me out ?
