title: How can I resolve this Data Gateway error from AAS model?
body: <p>I am receiving the following error when trying to deploy my model from Azure Analysis Services. The queries for the tables in the model work fine as set up in visual studio and process without error. I only get the following error when trying to deploy. I have checked the logs but they don't provide much help. Any help figuring out what is causing this error would be helpful.</p>
  
  <pre><code>Cannot process database. Reason: Failed to save modifications to the server. Error returned: 'An error occurred during On-Premise Gateway related activity. Additional error details: DM_GWPipeline_Gateway_MashupDataAccessError
  Received error payload from gateway service with ID 453958: Mashup expression evaluation error. Reason: ..
  Mashup expression evaluation error. Reason: .
  An error happened while reading data from the provider: 'Invalid operation. The connection is closed.'
  .
  
  Technical Details:
  RootActivityId: 541f9790-f5b5-4320-bf04-3b7f89a1ed18
  Date (UTC): 3/10/2020 2:49:18 PM
  An error occurred during On-Premise Gateway related activity. Additional error details: DM_GWPipeline_Gateway_CanceledError
  The operation failed due to an explicit cancellation. Exception: System.Threading.Tasks.TaskCanceledException: A task was canceled.
     at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
     at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
     at Microsoft.PowerBI.DataMovement.Pipeline.Dataflow.TDFHelpers.&lt;&gt;c__DisplayClass7_0`1.&lt;&lt;GetNextResponseAsync&gt;b__0&gt;d.MoveNext()
  --- End of stack trace from previous location where exception was thrown ---
     at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
     at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
     at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
     at Microsoft.PowerBI.DataMovement.Pipeline.Dataflow.TDFHelpers.&lt;&gt;c__DisplayClass11_0.&lt;&lt;ExecuteBlockOperationAsync&gt;b__0&gt;d.MoveNext()
  A task was canceled.
  </code></pre>