Job failed. Object reference not set to an instance of an object

Hello:
I am trying to create a script to create a DHCP scope, the DHCP servers are in different domains, therefore it needs credentials and I use an invoke-command to authenticate and run the script, but it gives me an error

This Script

Script contents

param(
[String]$ServerName,
[String]$StartRange,
[String]$EndRange,
[String]$Gateway,
[String]$NetMask,
[PSCredential]$Credential,
[String]$LeaseDuration,
[string]$Description,
[String]$Scope,
[String]$Name
)

Invoke-Command -ComputerName $ServerName -Credential $Credential -ScriptBlock {Add-DhcpServerv4Scope -Name $using:name -LeaseDuration $using:LeaseDuration -StartRange $using:StartRange -EndRange $using:EndRange -SubnetMask $using:Netmask -State Active -Type DHCP -Verbose -Description $using:Description} -Verbose

Product: PowerShell Universal
Version: 5.3.3