While running a Steel Path alert, I opened the rescue vault in the Grineer sea lab map moments before Mania spawned into the mission. The acolyte apparently deployed beyond a door that remains locked down until mission completion (NB: this door didn't even lead to extraction, which also struck me as unusual—not much reason to lock down a dead-end path). Mania proceeded to use his Tenno-teleporting ability, which pulled me across this impassable threshold, effectively stranding me in the dead-end room and forcing a mission abort. Maybe something to do with the sea lab map, I recall 'sharkwing' sometimes causing map continuity issues before.
Edit: It would seem I misidentified the issue, but there is still a less severe level-related problem to report. The door in question was outwardly reading as inactive (no lights to indicate it could be opened in any fashion, no console light to indicate hacking would work), but approaching the console revealed it could be opened like any shut door (i.e. no hacking required, just a button press). I jumped the gun on calling this progression-halting, but it's still an issue that could use a fix some time. It's a tad confusing to stumble across, obviously. :>