AWS API Gateway error: API Gateway does not have permission to assume the provided role as S3 proxy : <p>There are similar questions but they have answers that I have tried.
I'm not sure what I could be doing wrong but any help would appreciated.</p>

<p>Test details:
<a href="https://i.stack.imgur.com/MtkuV.png" rel="noreferrer"><img src="https://i.stack.imgur.com/MtkuV.png" alt="enter image description here"></a></p>

<p>The Error from a method-execution test; PUT request:</p>

<pre><code>Execution log for request test-request
Mon Oct 16 10:13:47 UTC 2017 : Starting execution for request: test-invoke-request
Mon Oct 16 10:13:47 UTC 2017 : HTTP Method: PUT, Resource Path: /pop-data-xmlz/test.xml
Mon Oct 16 10:13:47 UTC 2017 : Method request path: {item=test.xml, folder=pop-data-xmlz}
Mon Oct 16 10:13:47 UTC 2017 : Method request query string: {}
Mon Oct 16 10:13:47 UTC 2017 : Method request headers: {Content-Type=application/xml}
Mon Oct 16 10:13:47 UTC 2017 : Method request body before transformations: &lt;test&gt;
test string
&lt;/test&gt;
Mon Oct 16 10:13:47 UTC 2017 : Request validation succeeded for content type application/json
Mon Oct 16 10:13:47 UTC 2017 : Execution failed due to configuration error: API Gateway does not have permission to assume the provided role
Mon Oct 16 10:13:47 UTC 2017 : Method completed with status: 500
</code></pre>

<p>I am following the API Gateway To S3 tutorial (<a href="http://docs.aws.amazon.com/apigateway/latest/developerguide/integrating-api-with-aws-services-s3.html" rel="noreferrer">http://docs.aws.amazon.com/apigateway/latest/developerguide/integrating-api-with-aws-services-s3.html</a>) and attempting to execute a PUT request.</p>

<p>The API Gateway is in us-east-1 and the S3 bucket in us-east-2.</p>

<p>The created Role: <strong>APIGatewayProxyCustom</strong></p>

<p>A policy (pop-date-ingest) is attached that allows PUT request to S3 buckets.
<a href="https://i.stack.imgur.com/Rygj7.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Rygj7.png" alt="enter image description here"></a></p>

<p>The Role has a trust relationship set:
<a href="https://i.stack.imgur.com/7lZST.png" rel="noreferrer"><img src="https://i.stack.imgur.com/7lZST.png" alt="enter image description here"></a></p>
