Cannot connect to vCenter Server 6.5 with vSphere-Client after upgrade from 5.5 by wizard

[sgloeckle]

Hi

to prepare for future Projects I created a virtual testing Environment of

1 vCenter Server 5.5 based on Windows Server 2012 R2 (including vCenter Server Update Manager)

2 ESXi-Hosts 5.5

1 HP StoreVirtual VSA MultiSite Cluster

Aim: Upgrade vSphere Environment from 5.5 to 6.5.

Method: Vmware provided Migration Assistant

Upgrade Process did succeed so far. vCenter Server 5.5 has been successfully upgraded to vCSA 6.5 and all Settings and ESXi-Hosts are availible on migrated vCenter Server via vSphere Web-Client.

But: only Web-Client Access does work. It fails while connecting to vCSA by vSphere-Client with message:

An internal error occured in the vSphere Client.

Details: Object reference not set to an instance of an object.

I searched the log-file but still don't have a clue what's the cause of this Problem.

Anyone an idea how to solve the Problem?

thanks

[abhilashhb · Accepted solution]

This is a known behaviour.

Thick client (Desktop Client / C# / vSphere Client / VI Client for Windows) will not be available from vCenter 6.5.

Read point 3 : vSphere Client (HTML5) and vSphere Web Client 6.5 FAQ (2147929) | VMware KB