I’ve been getting quite a few reports back from people that after installing the latest Update Rollup 2 (UR2) on SBS 2011 Essentials and Windows Storage Server 2008 R2 Essentials, that the client computers have appeared offline and the backups have failed. I blogged about the release of UR2 earlier this month here. One of the things that I observed during the installation of the update on the server was the way in which it will force upgrade the client agent on the machines. It shows a small bubble popup indicating that the client machine needs to be rebooted as you can see below.
What happens under the covers, is that once the client agent has been upgrade, it can’t communicate with the server UNTIL after a reboot – therefore causing the client machine to appear offline in the console and causing backup to fail. The solution is simple. Reboot all your client computers after the agent has upgrade and then everything works fine. Your clients will appear online and backups will succeed once more.