Game version: 1.1.0.42
Mods: No

The Attack objective will not be completed in Combat ops Everon once all enemy AI's are killed in the AO. I have confirmed this bug dozens of times and even confirmed it using the Game Master in a hosted session to 100% confirm that not a single enemy AI was present in the AO. IT does this 90% of the time with a very few and rare exceptions where it actually completes the mission.

the exact same issue also applies to the "Support attack" mission. And this issue also Applies to Combat Ops Arland "Clear area" mission.