Patch attached to fix some lingering issues. One is that wxGLCanvas::OnSize() is deprecated in 3.0 - the portable (between platforms and wx versions) way to achieve this is to call event.Skip(); which will cause the event to be propagated to the base class. AIUI, the only platform this matters on is OS X, which I can't test on - it would be useful to confirm that resizing the window still works on OS X. The other was in my original patch, but got lost when it was applied. As a result wx3 gives an "assertion failed" if loch fails to load a file. The issue here is that the wxWindowDisabler needs to be off before the messagebox gets shown, which I had carefully arranged by reordering code and adding an extra { } block around just the section which needs protecting. I've added a comment this time, to document the reason for the extra { } block. Cheers, Olly