> It generates a two page notebook but page one has a small black square
> top left, this is even visible in the official demo. Any ideas what is
> going on?
> The square vanishes when changing pages and doesn't return until next run.
> (Python3.6, wxpython 4.0.0b2, windows10)
Yes, this is some kind of a bug in the notebook code that has been
around for a long time. It's not a real window, and it's not the
background showing through. Here's a thread from 2012 that talks about
the same issue, and my harebrained theory on what causes it:
The workaround is to force a refresh by adding this to your dialog's
wx.CallAfter( self.nb.Refresh )
Tim Roberts, ti...@probo.com
Providenza & Boekelheide, Inc.