Error after set org.kie.server.bypass.auth.user to true

After set the property , when trying to start process i am getting the following error
http://localhost:8080/kie-server/services/rest/server/containers/testCon/tasks/10/states/started'! Error code: 500, message: Unexpected error during processing: id to load is required for loading.

Below are code how i start the process:

String serverUrl = "http://localhost:8080/kie-server/services/rest/server";
String user = "Administrator";
String password = "test";
KieServicesConfiguration configuration = KieServicesFactory.newRestConfiguration(serverUrl, user, password);
KieServicesClient client = KieServicesFactory.newKieServicesClient(configuration);

UserTaskServicesClient taskClient = client.getServicesClient(UserTaskServicesClient.class);
taskClient.startTask("testCon", 10L, "test");

Anyone know why the error is happening.