Hi Liem Nguyen • ,
Welcome to Microsoft Q&A forum and thanks for using Azure Services.
As I understand, you are unable to create Azure Synapse Workspace with error code":"WorkspaceInNonTerminalState","message":"Workspace is in non-terminal state Failed and cannot be updated.
Could you please try deregistering Microsoft SQL and register again and then create Synapse Workspace, if this helps in your case?
If above does not help, you might have a stuck resource. As this is specific to your subscription, I'd like to refer you to support. They will be able to investigate and do necessary action.
If you do not have a support plan, please let us know so that we can help with other options to unblock you.
If this answers your query, do click Accept Answer
and Mark Helpful
for the same. And, if you have any further query do let us know.
Thank you.