Hello @Govindaswamy, Baskar ,
Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.
I understand that you are trying to create a Virtual Hub using PowerShell script in West Europe region on an existing Virtual WAN and it is failing with an InternalServerError.
I tried to create a Virtual Hub in my lab on an existing Virtual WAN and below are the commands that I used and they completed successfully:
Reference : https://video2.skills-academy.com/en-us/powershell/module/az.network/get-azvirtualwan?view=azps-7.5.0
https://video2.skills-academy.com/en-us/powershell/module/az.network/new-azvirtualhub?view=azps-7.5.0
Could you please use the below commands and try again?
$virtualWan = Get-AzVirtualWan -Name "NameofVWan" -ResourceGroupName "testRG1"
New-AzVirtualHub -VirtualWan $virtualWan -ResourceGroupName "testRG1" -Name "testVWan1" -AddressPrefix "10.78.252.0/24" -Location "West Europe"
Kindly let us know if the above helps or you need further assistance on this issue.
----------------------------------------------------------------------------------------------------------------
Please "Accept the answer" if the information helped you. This will help us and others in the community as well.