Azure released their new Azure Resource Manager (ARM) automation engine.
The problem is, some solutions are offered as ARM-only. If your using the "Classic" Virtual Network you will have to deploy a vNet using ARM to leverage the product.
Long term, you would want to create a connection between your "Classic" and newly created ARM vNet and use the Move-AzureResource cmdlet to migrate all your resources over. Then, decommission your "Classic" vNet.
Additional info regarding the Move-AzureResource cmdlet:
https://msdn.microsoft.com/en-us/library/dn986795.aspx