This article helps in troubleshooting issues with NSX apply during transition.
Issue of NSX solution apply task failing is observed when there are drifts in base image / any component as part of transition.
In the Apply NSX Solution task, below can be seen:
A general system error occurred: Solution apply failed because the vSphere Lifecycle image contains either a new ESXi version or a new addons version or new components. Please proceed to the vSphere Client Lifecycle Manager to update ESXi or addons or components along with the solution 'com.vmware.nsxt'
VMware Cloud foundation 9.0
vLCM transition workflow in SDDC Manager fails if NSX solution does not get set in the software spec of the cluster.
Currently there is no resolution.
Workaround:
Please refer to this document: NSX with vSphere Lifecycle Manager Scenarios.