how to call wekagp from matlab?pls help

javaaddpath('\weka.jar');

clear all
clc

import weka.classifiers.Classifier
import weka.classifiers.trees.J48
import weka.classifiers.Evaluation;

% calling classifier from matlab
v1 = java.lang.String('-t');
v2 = java.lang.String('train.arff');

v3 = java.lang.String('-T');
v4 = java.lang.String('test.arff');

prm = cat(1,v1,v2,v3,v4);

weka.classifiers.Evaluation.evaluateModel(javaObject('weka.classifiers.trees.J48'),prm);

and im getting error as

java exception
weka exception:keyword@relation excepted

[Walter Roberson]

"excepted" or "expected" ?