Mission `STR_ALIEN_INTERCEPTION_3` is missing the attribute `operationSpawnZone`.
Alien base (at the start of a new mission) cannot be spawned.
Report to the mod author (Orion's Shadow).
Actually, the whole setup is wrong.
The mission has `operationType`= 6, which suggests it should be used in Hunt missions only (generated by alien bases), but it is used here as a Retaliation mission (generated in dogfight).
Either remove it from possible retaliation missions (and make it a proper Hunt mission); or don't mark it as a Hunt mission and you can keep it as Retaliation mission.
