So, I was having the issue where I could not load into either of the Mythic Missions on Keplar. What I ended up doing was loading into the "World Tier Patrol" on Mythic difficulty. For some reason when I loaded in to Caldera it showed me having one of those an objective to plug one of those strangelet capsles things in, once I did that, I suddenly could load into the Mythic missions again. I hope this helps someone.