"Host %computername% has an agent that is not in a responding state and is not available for placement"

Hi,

I recently deployed Update Rollup 3 for VMM 2012 SP1.

There are 21 Hyper-V hosts which is managed by the VMM server. All agents was updated after the Update Rollup was installed on the VMM server. On 4 of the managed hosts I get the following error when trying to deploy a new Virtual Machine after the Update Rollup was deployed:

Host %computername% has an agent that is not in a responding state and is not available for placement.

Any idea what the problem might be? I tried to reboot one of the problematic hosts, without any improvement to the problem. The host status is "OK" in the Fabric view for all hosts. Also, I can`t see any related events in the event logs.