Description: When trying to connect to an external service provider using the Invoke REST API activity, it will fail if it has a vendor specific content-type. e.g., "application/vnd.whispir.message-v1+json".
Symptoms: Invoke REST API -> Input tab -> Header: Content-Type=application/vnd.whispir.message-v1+json
Error in output:
<StatusCode>415</StatusCode>
<ReasonPhrase>Unsupported Media Type</ReasonPhrase>
Cause: Invoke REST API activity supports mostly custom Content-Types, but there are some rules. If the custom Content-Type contains "xml","json","plain" or "html", regardless if its upper or low case, it will be replaced with "application/xml", "application/json","text/plain" or "text/html". Other Content-Types will not be replaced.