Error: Node version mismatch detected during upgrade precheck - VCF Operations for Networks 9.1.0

Products

• VCF Operations for Networks

Issue/Introduction

• When attempting to upgrade VCF Operations for Networks to version 9.1.0.0 via the VCF Operations Fleet Management UI (Build > Lifecycle > VCF Management > Upgrade), the upgrade precheck fails during the System Prechecks phase.
  
  
• The upgrade cannot proceed past the validation stage.

• The task progress stops during the System Prechecks phase. Reviewing the VCF Operations for Networks GUI reveals one or more Collector nodes with the status:

  Node version mismatch detected

• Refer to below screenshots from VCF Operations for Networks GUI showing error on collector.
  
  
  
  
  
• Same error can be seen on the individual collector in VCF operations for Networks GUI as well, refer to below screenshot:
  
  

Environment

• VCF Operations for Networks 9.0.x
• VCF Operations for Networks 9.1.x

Cause

In VCF 9.1, the Fleet Lifecycle service performs a nodes_health_check during pre-validation.
This check enforces strict version parity across the cluster. The failure occurs when a Collector node is running a different software version than the Platform nodes (often seen with newly deployed collectors that were not provisioned using the correct matching OVA), preventing the orchestration engine from establishing a valid upgrade baseline.

Resolution

To resolve the precheck failure and proceed with the VCF 9.1 upgrade, the mismatched node must be removed or synchronized.

1. Identify the Mismatched Node: Log into the VCF Operations for Networks GUI and navigate to the Member Nodes view to identify the specific Collector(s) reporting the version mismatch.
2. Decommission the Node: If the mismatched collector is a recent deployment or is non-critical, delete the node from the configuration.
3. Lifecycle metadata sync : After deleting the node, perform Lifecycle metadata sync  to ensure the Fleet Lifecycle Manager has the updated cluster state.
4. Re-run Precheck: Return to the Fleet Management UI and re-run the Upgrade Precheck. The System Prechecks should now complete successfully.

Additional Information

IMPORTANT: 

Before proceeding with the actual upgrade after a successful precheck, you must follow the specific procedure and order for taking snapshots as documented in  KB 314428.
Failure to follow the correct snapshot order can lead to data inconsistency during the upgrade rollback if needed.