What happens? It's 2.9MB update.
Nothing mate, on mine it downloaded, rebooted, stalled on the first update bar and rebooted to recovery by itself. I pressed reboot and it booted back up normally but the update to install notification changed to update failed. I vaguely remember a message when I installed ROM before I rebooted, said something like stock ROM may replace recovery on reboot and asked if i wanted to prevent it so I pressed yes. Maybe its also preventing this but i'd have thought it's the right option to press.
I also note there's another thread going on where someone's just disabled the update centre to get rid of the notification. While technically a solution we then won't get updates to the Sony apps I think so not so good as more than a temporary fix.
It appears to me that some remains of .199 have hung around on this build, maybe the kernel? In my capability.xml file I have <app> <productrevision> 9.2.A.1.199 but <filesystem> <productrevision> 9.2.A.1.205. I'm sure this is exactly how it was in peetr's hybrid ROM when he was using .295 firmware on the .276 kernel. It only showed in this file and there was a permanent update notification to .295 because of the kernel discrepancy.