Problems with the integration of Java and mantis

I hope someone can help me with some solution for this error which I can not find a solution for.

I am trying to integrate java with mantis, everything was fine until I try to add an Issue (problem).

In this part, the system shows me the following error:

org.mantisbt.connect.MCException: Error Type: SYSTEM NOTICE,
Error Description: Object of class SoapFault could not be converted to int

But, I only use this in the code:

            issue.setProject(new MCAttribute(project.getId(), 
            project.getName()));
            issue.setAdditionalInformation(null);
            issue.setOs(System.getProperty("os.name"));
            issue.setOsBuild(System.getProperty("os.version"));
            issue.setPlatform(System.getProperty("os.arch"));
            issue.setSeverity(new MCAttribute(70, "crash"));
            issue.setReproducibility(new MCAttribute(10, "always"));
            issue.setSummary(Abstract + new Date());
            issue.setDescription(Description);
            issue.setCategory(Category);
            issue.setPriority(new MCAttribute(40, "high"));
            issue.setAdditionalInformation(Information);
            //this part is the real trouble :
            Session.addIssue(issue);

Thanks to everyone !!!