Error With Running Tic Tac Toe Program?

So my class was recently given an assignment to make a Tic Tac Toe program with options of playing against the computer, or another person. I was able to 2 player game work, but I have run into a problem with the two player game. Whenever I start debugging and click on one of my buttons (these represent the 9 spaces on a tic tac toe board), the gameplay form freezes, and becomes uncontrollable. The close button on the form doesn't even work, I have to go back to VB and click stop debugging to close the unresponsive form. I checked my original two player game, which has a similar code, but that works just fine. VB does not show any error messages or give any warning.

Option Strict On
Public Class frmGameplayEasy
Dim intTurn As Integer = 1

[code]......