ssh to cloudKey
cd /tmp/ wget https://help.ubnt.com/hc/en-us/article_attachments/360008640574/CK_repair.js
service unifi stop
mongod --dbpath /usr/lib/unifi/data/db --smallfiles --logpath /usr/lib/unifi/logs/server.log --repair
mongod --dbpath /usr/lib/unifi/data/db --smallfiles --logpath /usr/lib/unifi/logs/server.log --journal --fork (if you get an error try to remove --journaled )
mongo < /tmp/CK_repair.js
mongod --dbpath /usr/lib/unifi/data/db --smallfiles --logpath /usr/lib/unifi/logs/server.log --shutdown
service unifi start