As per the KB 2148819 , TLSv1.0 has been disabled from the VC and issue started to connect the VC from the desktop client and also using the powercli .
Error from the Desktop client:
Error from the Powercli
Using the web-client there is no issue on connecting the vcenter or ESX hosts and only the issue is from the desktop client and powercli . After reading the KB again noticed that they already mentioned in notes about the issue and pointed to the another KB 2149000 which describes the issue and add to do few changes on the below file with few MS .Net patches
C:\Program Files (x86)\VMware\Infrastructure\Virtual Infrastructure Client\Launcher\VpxClient.exe.config
Edit the VpxClient.exe.config file by setting the parameters
<add key = "EnableTLS12" value = "false" /> as
<add key = "EnableTLS12" value = "true" />
After doing the changes also had the same issue and finally it got resolved by re-installing the desktop client.
But still connecting the vCenter using the powercli was not fixed and finally found the another KB 2137109 which asked to do the below registry changes which fixed the issue.
- For 32-bit processes, change the following registry key value to 1.
- For 64-bit processes, in addition to the above registry key, change the following registry key value to 1.