As the name implies I can't complete it.

Killed all the synth in the area walked around the area 5 times set of all the mines even nocliped to see if there where any enamies stuck in the walls or something. Nothing helped. Went into the university basemant got the gun.

I had not visited the area before this mission.

General actions so far in the game that might be of importance.

Upper half of the map largely explored. Lower half almost none.

Completed semper invictea after the zepellin showed up. Thats also as far as I am in the main quest.

Did a lot of the settlement mission but not all.

Did quite some railroad missions (all after the zeppelin showed up)

Is there some command where I can force the game to complete the objective?

To end on a good note. Love the game keep up the good work with the bug fixes.