I have removed it. But it is the same. After reset of RAP I can see "upgrading", then "rebooting", after reboot it ends up with "up", flag "Rc2ID".
###
AP Database
-----------
Name Group AP Type IP Address Status Flags Switch IP Standby IP
---- ----- ------- ---------- ------ ----- --------- ----------
00:0b:86:66:3a:d0 rap RAP-5WN 10.1.1.44 Up 6m:34s Rc2ID 192.168.1.2 0.0.0.0
00:1a:1e:10:15:37 default 93H 192.168.1.95 Up 22d:20h:38m:19s 192.168.1.2 0.0.0.0
00:24:6c:cb:55:a9 default 105 192.168.1.94 Up 22d:20h:37m:56s 192.168.1.2 0.0.0.0
00:24:6c:cc:5b:92 default 93 192.168.1.97 Up 22d:20h:38m:5s 192.168.1.2 0.0.0.0
###
Maybe I have some bad configuration. Can I find some functional configuration example?