I completed the Vexcalibur first mission and i got the Vexcalibur from the boss at the end, then i went to the war table and picked up the quest to upgrade the weapon killing vex, but the quest is nowhere to be found, i checked the abbandoned quest post and my 3 characters, I even did the quest on another character, but I cant get the quest to progress on the vexcalibur mission, does anyone know what to do?