given a document "file.docx" located in a library "documents". When I enter http://server.site/_api/web/GetFileByServerRelativeURL('/site/documents/file.docx'), into the browser, I receive a correctly detailled xml view. When I use the same URL for a REST call in a ShP 2013 Designer workflow as a GET method (the required dictionary with the accept header 'application/json;odata=verbose' has been created aforehand), it fires a http500 error. What am I doing wrong? Thank you in advance for your support!