diff -r 12cb48823b8c -r 3c94bac4526e controls/CustomToolTip.py
--- a/controls/CustomToolTip.py	Tue Jun 26 14:48:44 2018 +0300
+++ b/controls/CustomToolTip.py	Tue Jun 26 17:34:15 2018 +0300
@@ -137,7 +137,7 @@
         max_width = max_height = 0
 
         # Create a memory DC for calculating text extent
-        dc = wx.MemoryDC()
+        dc = wx.MemoryDC(wx.EmptyBitmap(1, 1))
         dc.SetFont(self.Font)
 
         # Compute max tip text size