stuck in the game=( (Rise of the Tomb Raider)

stuck in the game, at the research station. transported back through the camp, ran, assembling artifacts and all sorts of documents. wanted to go back to camp and to travel, but can't go down the stairs to the camp. as if over a ladder pack, and can not come down. I thought back to the control point, and everything will be fine, but unfortunately was transferred to the control point as well on this ladder that I can't go down. restarted the console. all the same. it's a shame, the game was 70%, I would not want to go again. what to do?!how to fix it
thought that another exit will be released, but there is then a dead end!

playing on xbox one