While initiating the NSX upgrade (System->Upgrade) process, the upgrade module indicates that a previous upgrade is still in progress, and the upgrade summary shows that the 'Upgrade Hosts' phase is incomplete. The current version and target version showing the same. As shown below:
When you click 'Continue' to check the full status, you will see that the Edge upgrade has completed successfully. However, the 'Hosts upgrade' phase is paused for one of the host clusters, even though all the members in that cluster are showing as fully upgraded. Meanwhile, the 'Manager upgrade' phase has also completed, which is the next phase following the hosts upgrade in the NSX upgrade process. As shown below:
VMware NSX
The cluster that participated in the previous upgrade, including all the hosts that were part of it, has been removed. As a result, neither the cluster nor its hosts are part of NSX anymore. However, this has left behind a stale entry, which is causing the issue.
GET https://<MPIP>/api/v1/transport-nodes/<Transport-Node-UUID>/state
DELETE https://<MPIP>/api/v1/transport-nodes/<Transport-Node-UUID>?force=true&unprepare_host=false
GET https://{{MPIP}}/api/v1/transport-nodes/<Transport-Node-UUID>/state