Getting the Sirius permit was "easy" for me (though I realized late that you need Allied status, not simply Friendly like Marco Qwent description suggest on the Engineer panel).
However, getting that damn Qwent invitation mission was a hassle. For about one hour I tried to switch solo/open to refresh mission board, fly to other stations / systems where Sirius Copr was the controlling faction...nada. Then after a few more refreshes of the MB, I got it.
Frustrating and wasting time as "hell".
I'm having this experience currently as well. Flipped modes for an hour until I gave up. I'm at Patterson, with a good amount of MT just waiting for the invitation to drop. I've tried going over to Avik to do some missions, that didn't help. Now I'm just doing some wake scanning outside patterson and checking the MB every now and again hoping for some change. Not sure why this last part of the time sink has to be so random and without hint.
If all I had was what was in the game, I'd have zero clue what to do next. As it is, I'm questioning whether it's still working as it did for some of you here. Does it drop specifically from Sirius Corp? Seems like an obvious answer, but I keep checking all factions anyhow, just in case.
Is there any other special requirement required for the mission to drop? Does Sirius Corp have to be the controlling faction for it to drop? Could it drop at Avik as well? Does flying back and forth between the two systems make any difference or should I just keep mode switching at Patterson until it eventually drops.
Not sure what's gained by this being so difficult. It's not like I've not put in a decent amount of time gaining Sirius Rep, leveling up Elvira, and loading up on Modular Terminals.
