Request Failed: Machine xxxxx: CustomizeVM: [CustomizeVM_Task] - A specified parameter was not correct. spec.identity.userdata.ComputerName

Recently one of my client was getting this error message "Request Failed: Machine xxxxx: CustomizeVM: [CustomizeVM_Task] - A specified parameter was not correct. spec.identity.userdata.ComputerName" when he was requesting the machine from windows blueprint Here is screenshot of error message:-

so issue was with the machine prefix because he did the mistake in the machine prefix configuration. linux was accepting but windows was not accepting the same configuration as prefix was using only number not any alphabet and this was reason of this issue. Finally i changed the machine prefix and issue gets resolved :)