Error: "does not have sufficient capacity to license the hosts added to this vCenter instance" when adding a host to vCenter in VCF 9.1

Products

• VMware vCenter Server

Issue/Introduction

In a VCF 9.1 environment, ESXi 8.0 cannot be added to vCenter after assigning a vSphere 8 license, resulting in an error indicating that Version 9+ license capacity is insufficient:

Environment

VMware Cloud Foundation 9.1

VMware ESXi 8.0

Cause

There is insufficient Version 9+ license capacity. ESXi 8.x hosts must be licensed with a pre-version 9 license key, and they also consume license capacity from your version 9+ license from your VCF or vSphere Foundation subscription. 

Resolution

Increase the Version 9+ license capacity in addition to the vSphere 8 license capacity. (For more details, see Mixed-Version Environments)