Error: Incompatible Host Profiles and authentication failure during vCenter Server 9.1 upgrade Stage 2 pre-check

Products

• VMware vCenter Server

Issue/Introduction

While upgrading vCenter Server from 8.0u3 to 9.1, the Stage 2 pre-check fails. The user may see errors regarding incompatible Host Profiles or Distributed Switches. In some instances, the deployment wizard may prompt for credentials that fail to authenticate, even if the credentials are valid for SSH.

Symptoms:

• Upgrade pre-check flags Host Profiles as incompatible with version 9.1.
• Errors mention Distributed Switches during the validation phase.
• A login prompt appears during Stage 2 that does not accept valid credentials.
• Unable to generate logs through the upgrade wizard prompt.

Environment

vCenter Server 8.0u3 (Source)
vCenter Server 9.1 (Target)
VMware Cloud Foundation 9.x

Cause

The upgrade pre-check identifies legacy Host Profile metadata that does not meet the schema requirements for vCenter 9.1. The authentication failure typically occurs when the upgrade wizard enters a transient state following a failed validation check.

Resolution

1. Log in to the source vCenter Server using the vSphere Client.
2. Navigate to Menu > Policies and Profiles > Host Profiles.
3. Identify the Host Profiles flagged in the upgrade pre-check.
4. Right-click the identified Host Profile and select Delete.
5. If the upgrade wizard is hung at an authentication prompt, close the wizard.
6. Open a browser and navigate to the Virtual Appliance Management Interface (VAMI) of the new vCenter 9.1 appliance (e.g., https://<new_vcenter_ip>:5480).
7. Log in as root and resume the Stage 2 process.
8. Run the pre-check again to ensure it passes.
9. Proceed with the upgrade.

Additional Information

If the issue persists with Distributed Switches, ensure all switches are upgraded to a version compatible with the source vCenter before attempting the 9.1 upgrade.