// send the request
HttpResponse oResponse = http.send(oRequest); // Exception line

if(oResponse.getStatusCode() == 200){ system.debug('statusCode'+oResponse.getStatusCode());

Map<String,Object> result = (Map<String,Object>)JSON.deserializeUntyped(oResponse.getBody());

updateCurrentConfiguration(String.ValueOf(result.get('access_token')),
Integer.valueOf(result.get('expires_in')), oConfiguration.Id);