When running a backup of replication job in vRanger 1 or more vms may fail with an error message "Operation timed out". When looking at Tasks and Events in the vSphere client you may notice an error similar to "Unable to complete the task as another task is already in progress".
This may be due to a process on the ESX(i) host being hung.
To resolve this issue restart the VMware Management Agents on the ESX(i) host.
See this VMware KB on how to restart the Management Agent.
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003490
