strange log

i have pc based router.after upgrade from 2.9.40 to 2.9.41 in logs I can see this:
02:08:41 system,info installed system-2.9.41
02:08:42 system,info installed wireless-2.9.41
02:08:42 system,info installed advanced-tools-2.9.41
02:08:42 system,info installing system-2.9.12…
02:08:42 system,info installation of system-2.9.12 was successful
02:08:42 system,info router rebooted

routeros version now is 2.9.41.but what mean last 2 lines?

in older versions, there was a bug which didn’t show some log lines. now the bug is fixed, and all the lost log lines have been shown to you. you can just ignore those log lines.