title: Dealing with seemingly undocumented error code from Azure Blob Storage batch operations: TlsVersionNotPermitted
body: <p>I've been dealing with some very strange behavior using the Azure.Storage.Blobs.Batch NuGet package. When trying to perform a batch delete operation, the request fails with a TlsVersionNotPermitted error code.</p>
  <p>Azure actually provides a list of possible error codes that Blob Storage can return here: <a href="https://docs.microsoft.com/en-us/rest/api/storageservices/blob-service-error-codes" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/rest/api/storageservices/blob-service-error-codes</a>
  but this error code is nowhere to be found in the list. A google search for &quot;TlsVersionNotPermitted&quot; literally yields no results, so I am pretty confused about how and why this error occurs.</p>
  <p>If anyone has any knowledge about what could cause this I'm very interested in hearing about it.
  Everything works fine with the non-batch operations by the way.</p>
  <p>Thanks in advance.</p>