title: Unable to export RDS snapshot to S3: The Principal export.rds.amazonaws.com isn't allowed to assume the IAM role
body: <p>I have this error when I'm trying to upload an RDS snapshot to the S3 (in the same region), although I have the correct IAM role:</p>
  <pre><code>{
    &quot;Version&quot;: &quot;2012-10-17&quot;,
    &quot;Statement&quot;: [
      {
        &quot;Sid&quot;: &quot;&quot;,
        &quot;Effect&quot;: &quot;Allow&quot;,
        &quot;Principal&quot;: {
          &quot;Service&quot;: &quot;export.rds.amazonaws.com&quot;
        },
        &quot;Action&quot;: &quot;sts:AssumeRole&quot;
      }
    ]
  }
  </code></pre>
  <p>Error message:</p>
  <pre><code>Your request to export snapshot to S3 has failed.
  The Principal export.rds.amazonaws.com isn't allowed to assume the IAM 
  role arn:aws:iam::030578524176:role/service-role/rds-export-role or 
  the IAM role arn:aws:iam::030578524176:role/service-role/rds-export- 
  role doesn't exist.
  </code></pre>