VMware has become aware of an issue that may occur wherein vCenter Server 5.x does not function correctly when installed with Oracle 11.2.0.3 Patch 10.

Symptoms may include:

• vCenter Server 5.0 and 5.1 does not function correctly when installed with Oracle 11.2.0.3 Patch 10
• Creating a virtual machine fails when vCenter Server 5.0 Update 1b or vCenter Server 5.1 is installed on Oracle 11.2.0.3 Patch 10
• You experience issues after installing vCenter Server 5.0 Update 1b or vCenter Server 5.1 with Oracle 11.2.0.3 Patch 10
• When creating a new virtual machine on vCenter Server 5.x, you see the error:

An internal error occurred in the vSphere Client.
 Details: Object reference not set to an instance of an object.

For further updates and more information on this alert, refer to KB article:
vCenter Server 5.x does not function correctly when installed with Oracle 11.2.0.3 Patch 10 (2039874).

UPDATE: This issue has been resolved with a new patch. Read more here…