"Object reference is not set to an instance of an object"?

In my dice game, whenever I press a roll button, I get this error in my function to check if there is a three of a dice: "Object reference is not set to an instance of an object"

Here is my code:

Private Function checkingthreeof1() As Boolean
        For i = 0 To 5
            If faces(i) >= 3 Then 'This is where the error is
                threeof = i + 1
                checkingthreeof2(True, 0)
            End If
        Next
        Return True Or False
    End Function

I looked all over Google but couldn't find a solution.