@Tanksy,This is not easy to explain

FAF has several bugfixes and enhancements compared to the vanilla/steam game.
As example;
The vanilla game is using 8 different Weapons to create a nuke explosion.
Let's say they are named "NukeACU", "NukePARAGON", "NukeMissile" etc.
In FAF we merged those 8 weapons inside one weapon and named it "NukeForall".
This change was made to reduce repeated code and make the game faster.
Normal units can handle this without any patch.
But now the mod-author decided do give his T1 land scout a nuklear weapon.
And because there is no "NukeScout" weapon, he is using a weapon from another unit like "NukePARAGON" instead of creating his own "NukeScout" weapon which would work with FAF.
But FAF has no longer a "NukePARAGON" only a "NukeForall".
And the unit crashes.
You can start the FAF gameversion directly without starting the FAforever Lobby by clicking the executeable:
C:\ProgramData\FAForever\bin\ForgedAlliance.exe
But you can't use this for steam, because FAF does not change any original files.
@RavenCurowThanks i will look at it.