1. From vCenter 6.7.0.42100 to version 6.7.42200
2. Running on same vCenter (embedded)
3. From the Appliance Management UI the Update section.
I also took the working vCenter with the Update Manager plugin, copied all the files in /etc/vmware/vsphere/vspere-ui/cm-service-packages/com.vmware.cis.vsphereclient.plugin and replaced them with the not working vCenter with Update Manager. The only difference between those 2 vCenter servers in that folder is the not working vCenter has a folder in that location of com.vmware.imagebuilder.imagebuilder-6.7.