Let's see if this is working now. When I have some issues, I change to my second computer, sometimes it works with a new computer.

common.py

@@ -0,0 +1,15 @@
+HOR_SEP_LEN = 3
+VER_SEP_LEN = 3
+DIAG_SEP_INNER_LEN = 2
+DIAG_SEP_OUTER_LEN = 3
+PAD = 4
+TOKENS_PER_PLAYER = 4
+
+PLAYER_COLORS = {
+    0: 'blue',
+    1: 'red',
+}
+PLAYER_NAMES = {
+    0: '1 (Blue)',
+    1: '2 (Red)',
+}