Your LimeSurvey version: [5.3.5]
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I am trying to export my survey results as PDF, using the LimeSurvey WebApi.
The result ist always null.
If I add the optional survey groupids parameter, there is an error message in the response: "Error: Invalid group ID"
But I am hardcoding the correct group ID...

My Post method looks as follows:
                    client.Method = "export_statistics";
                    client.Parameters.Add(JsonRpcClient.SessionKeyParamName, sessionKey);
                    client.Parameters.Add("iSurveyID", 133394);
                    client.Parameters.Add("docType", "pdf");
                    client.Parameters.Add("sLanguage", "de");
                    client.Parameters.Add("graph", true);
                    client.Parameters.Add("groupIDs", Newtonsoft.Json.Linq.JToken.FromObject(groupids));
                    client.Post();

Please help me...