New-VM is bombing out my script

Here’s my code:

[CmdletBinding()]
        Param(
      [Parameter(Mandatory=$True,HelpMessage="Enter one or more computer name(s) and IP address(es)")]
      [string[]]$ComputerName
        )
        Connect-VIServer -Server vcenterserver -Verbose
        $TargetCluster = Get-Cluster -Location "cluster" -Verbose
        $SourceVMTemplate = Get-Template -Name "Template" -Verbose
        $SourceCustomSpec = Get-OSCustomizationSpec -Name "Windows 2012 R2" -Verbose
        ForEach ($Computer in $ComputerName) {
            Write-Verbose -Message "Preparing to deploy [$Computer]." -Verbose
            $IPAddress = Read-Host -Prompt "Please enter IP Address"
            $SubnetMask = Read-Host -Prompt "Please enter Subnet Mask"
            $DefaultGateway = Read-Host -Prompt "Please enter Default Gateway"
            $DNSServerPrimary = Read-Host -Prompt "Please enter primary DNS address"
            $DNSServerSecondary = Read-Host -Prompt "Please enter secondary DNS address"
            Write-Verbose -Message "Deploying Virtual Machine with Name: [$Computer] using Template: [$SourceVMTemplate] and Customization Specification: [$SourceCustomSpec] on Cluster: [$TargetCluster] and waiting for completion"  -Verbose
            Start-Sleep -s 60
            New-VM -Name $Computer -Template $SourceVMTemplate -ResourcePool $TargetCluster -OSCustomizationSpec $SourceCustomSpec -Verbose
            Write-Verbose -Message "Virtual Machine $Computer Deployed. Powering On" -Verbose
            Start-Sleep -s 120
            Start-VM -VM $Computer -Verbose
            Start-Sleep -s 300 -Verbose
            Set-OSCustomizationNicMapping -IpAddress $IPAddress -SubnetMask $SubnetMask -DefaultGateway $DefaultGateway
            Set-DnsClientServerAddress -InterfaceIndex 12 -ServerAddresses ("$DNSServerPrimary","$DNSServerSecondary")
            Stop-VM -Server $Computer
            Set-NetAdapter -Name "Net adapter" -VlanID Vlan#
            Start-VM -Name $Computer
}

When I run this code, I return the following error:

New-VM : 7/24/2017 2:09:59 PM   New-VM          Operation is not valid due to the current state of the object.
At line:19 char:13
+             New-VM -Name $Computer -Template $SourceVMTemplate -Resou ...
+             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [New-VM], VimException
    + FullyQualifiedErrorId : Core_BaseCmdlet_UnknownError,VMware.VimAutomation.ViCore.Cmdlets.Commands.NewVM 

I’ve thrown in the Start-Sleep cmdlets for troubleshooting, but I honestly can’t figure out what is flagging the issue. Thoughts?

I’d probably toss in a breakpoint to stop the script right before New-VM, and then try running it manually. Something you’re passing the command is making it choke, but it’s all server-side, so without being there with you in person to futz with it, it’s hard to say exactly what. But it’s one of your parameters, I expect.

Duly noted, I’ll dig in further. Odd thing is the error isn’t causing the script to stop, at the moment, it just alerts then continues. Maybe it’s less of a problem than I thought it was.