[admin@admin ~]# apt-get update
Hit:1 http://archive.ubuntu.com/ubuntu bionic InRelease
Ign:2 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 InRelease
...
Get:8 http://dl.ubnt.com/unifi/debian stable InRelease [3024 B]
Reading package lists...
E: Repository 'http://dl.ubnt.com/unifi/debian stable InRelease' changed its 'Codename' value from 'unifi-5.10' to 'unifi-5.11'