Problem with Sharepoint REST API CopyTo

Following problem with using ShP 2013 enterprise on premises and ShPDesigner2013:

  1. Given a site http://server/site which holds two document libraries “docs1” and “docs2”. Both libraries hold *.docx documents.
  2. The task: Create a ShPDesigner2013 workflow (for some reasons I can’t use Visual Studio) which copies the selected document (current item) from docs1 to docs2.
  3. My problem: I have correctly built the request header (Accept - String - application/json;odata=verbose), but the “Call http web service” action with method=POST and http://server/site/_api/web/lists/GetFileByServerRelativeURL('/docs1/test.docx')/copyTo(strNewUrl='/server/site/docs2/test.docx',bOverwrite=true) doesn’t work, it cancels with the following error message:

RequestorId: ad9824d3-039b-698e-615a-71e2f4b554df. Details: System.ApplicationException: HTTP 500 {“Transfer-Encoding”:[“chunked”],”X-SharePointHealthScore”:[“0″],”SPClientServiceRequestDuration”:[“54″],”SPRequestGuid”:[“45bc2344-b620-4a4a-850b-0d5476b09e4e”],”request-id”:[“45bc2344-b620-4a4a-850b-0d5476b09e4e”],”X-FRAME-OPTIONS”:[“SAMEORIGIN”],”MicrosoftSharePointTeamServices”:[“15.0.0.4841″],”X-Content-Type-Options”:[“nosniff”],”X-MS-InvokeApp”:[“1; RequireReadOnly”],”Cache-Control”:[“max-age=0, private”],”Date”:[“Tue, 26 Jun 2018 11:46:32 GMT”],”Server”:[“Microsoft-IIS/8.5″],”X-AspNet-Version”:[“4.0.30319″],”X-Powered-By”:[“ASP.NET”]} at Microsoft.Activities.Hosting.Runtime.Subroutine.SubroutineChild.Execute(CodeActivityContext context) at System.Activities.CodeActivity.InternalExecute(ActivityInstance instance, ActivityExecutor executor, BookmarkManager bookmarkManager) at System.Activities.Runtime.ActivityExecutor.ExecuteActivityWorkItem.ExecuteBody(ActivityExecutor executor, BookmarkManager bookmarkManager, Location resultLocation)

What am I doing wrong?