This issue may occur if the TCP connection between the ESX host and the License Server is slow or if the License Server itself is slow.
You must resolve latency issues.
To resolve latency issues:
Ensure that there is no latency in network connectivity between VI Client and the ESX host or between the ESX host and the License Server.
Check that there is no problem with License Server performance.
If you cannot resolve latency issues, install and configure the License Server on a different machine and license the ESX host using the new License Server.
Based on VMware KB 1007358