Symptoms
- Upgrading from vCenter Server (VirtualCenter) 2.5.x to vCenter Server 4.0 fails
- You cannot upgrade from vCenter Server 2.5.x to vCenter Server 4.0
- After entering credentials for your DSN, you see the error:
Setup failed with an unknown error during DSN validation
Resolution
This issue can occur if you are using an incompatible ODBC client driver or if the current driver is corrupt.
To ensure you are using the correct ODBC driver, see the vSphere Upgrade Guide.
If the driver version is correct, then it is likely corrupted and needs to be reloaded. Contact your vendor for more information.
based on VMware KB 1022249
