test won't run, compilation has ended

I am running a test file for a code we had to run but it won't run the test. It says can't run compilation has ended. I've searched endlessly and can't seem to find the issue. Everything is written the way it should be. Hope you guys can assist me, much appreciated. The error I am receiving is:

ScoreDiceTest.java:7: error: scoreWithNumbers(int,int) has private access in ScoreDice

The test I ran is:

public class ScoreDiceTest{ @Test `public void testBoth6(){ assertEquals(10, ScoreDice.scoreWithNumbers(6,6)); }