Explanation
The most likely reason why the systems administrator gets an error while executing a vertical-scaling test of the vCPU on the VMs is that there is a licensing issue with the virtualization software or the operating system.
Some virtualization software or operating systems have limitations on how many vCPUs can be assigned to each VM or each host, depending on the license type or edition. The systems administrator should check the license agreement and requirements and ensure that they are compliant with them. Reference: CompTIA Cloud+ Certification Exam Objectives, Domain 4.0 Troubleshooting, Objective 4.3 Given a scenario, troubleshoot capacity issues within a cloud environment.