This happened to not just me, but every single person who participated in the event seemed to have experienced it... Almost all of the enemy vex that spawned in this event, including the spire and the pressure plates were all invisible. The enemies could still be killed and would fire at you, and you could still activate the plates, but their models were not spawning in for some weird reason... We inevitably lost the event because we couldn't even see the enemy vex integrating with the spire. This is quite possibly the weirdest and most hysterical bug I've encountered yet, and I thought I'd mention it so you can see if there's anything causing it...