Hi Hamed, Ali,
Thank you for reaching out to us on the Microsoft Q&A forum.
Based on the error inputs provided by you, we have successfully reproduced the exercise titled ‘Exercise - Implement a hub-spoke network topology in Azure’ from Unit 4.
As per the error you shared, kindly wait until the resource is created in the Azure Cloud Shell. After the resource creation is complete, you can log in to the Azure portal linked with the Azure sandbox environment and proceed with the remaining steps as per the Learn Path. You will be able to complete the unit.
Please note that if any previous sandbox processes are running, close them before proceeding. Wait until the previous session is closed, or you can manually sign out from the Azure portal or exit from the Azure Cloud Shell.
If the information is helpful, please accept the answer by clicking the "Upvote" and "Accept Answer" on the post. If you are still facing any issue, please let us know in the comments. We are glad to help you.
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