Added error for staging resource group

When the staging resource group is specified with the same name for two different image templates, an "InternalOperationError" error is thrown.

Author: jamasten

articles/virtual-machines/linux/image-builder-troubleshoot.md

@@ -105,7 +105,7 @@ Microsoft.VirtualMachineImages/imageTemplates 'helloImageTemplateforSIG01' faile
 ```
 #### Cause
 
-In most cases, the resource deployment failure error occurs because of missing permissions.
+In most cases, the resource deployment failure error occurs because of missing permissions. This error may also be caused by a conflict with the staging resource group.
 
 #### Solution
 
@@ -114,6 +114,8 @@ Depending on your scenario, VM Image Builder might need permissions to:
 - The distribution image or Azure Compute Gallery resource.
 - The storage account, container, or blob that the `File` customizer is accessing. 
 
+Also, ensure the staging resource group name is uniquely specified for each image template.
+
 For more information about configuring permissions, see [Configure VM Image Builder permissions by using the Azure CLI](image-builder-permissions-cli.md) or [Configure VM Image Builder permissions by using PowerShell](image-builder-permissions-powershell.md).
 
 ### Error getting a managed image