MDB_SSGM_Vehicle destroys the vehicle object if the mode is not 1 or it isn't a harvester.
It does this on the ::Created event here:
void MDB_SSGM_Vehicle::Created(GameObject *obj) {
if (Settings->GameMode != 1 && !Is_Harvester_Preset(obj)) {
Commands->Destroy_Object(obj);
}
else if (!Data->Mod && Settings->EnableVehicleDamageAnim) {
Commands->Attach_Script(obj,"MDB_SSGM_Vehicle_Damage_Animation","");
}
}
If you want your purchase vehicle chat hook to work properly in CTF mode then you will have to remove this line:
Commands->Destroy_Object(obj);
This way butchers the script really, as that would mean vehicles could be created in all modes, but if you are just running a plain ctf server with no other maps using other modes I can;t really see the harm.
If you are using other modes for other maps on the same FDS then please say so, as you will need to do something else entirely to make it work as intended.