[Lucika]

Is it possible to convert a FRED2 (retail) created mission to FSO?

[Mobius]

Sure, why not? All you need is to open the mission with FRED 2 Open. You will then be able to add new features, like the skybox. Importing an old mission in FRED2 Open is easy, it's importing a FRED 2 Open mission in FRED2 that gives more problems.

This should work, in theory. I say this because certain old mission might not work properly. Such episodes are rare, though.

[Polpolion]

You don't need to convert FRED2 missions to FSO. They are completely compatible in that direction.

The trouble comes in when you are trying to play FSO missions in retail Freespace. FRED2 Open added features; it did not take any features out. Thus, the only time you need to worry is when you may be using features in FRED2 Open that are not in retail FRED2.