Uninstalling NSX components on a cluster hung/stuck in Uninstalling

On a VMware cluster where the NSX components were installed on the hosts, we had them removed. The bits where removed from the hosts, the hosts were also rebooted, but the NSX UI in vSphere Web Client shows the Uninstalling to appear stuck: the Installation Status on the cluster says Uninstalling while on the hosts the status is In progress ... and spinning; and this never completes.

The solution provided by VMware support was:

 - go in vSphere Web Client to Administration:

 - There click vCenter Server Extensions, and then click vSphere ESX Agent Manager:

 - Under vSphere ESX Agent Manager click the Manage tab and you will see the Agencies installed per your clusters. In our case the stuck one was showing as Uninstalled. Right-click it and click Delete Agency. A few tasks will be started on the hosts. Wait a few, and then refresh the Manage menu. During the operations its Status might turn to Warning, and when all tasks will finish it will disappear from the list.

 - Going back to Networking and Security menu, Installation sub-menu, the cluster should look OK.