Hi Bokeh Users -
We’ve confirmed an incompatibility with Bokeh Server applications and the new Tornado v4.5 release. A current workaround is to downgrade Tornado to v4.4.2 as we work to diagnose and resolve this issue. You can track the progress of this issue at https://github.com/bokeh/bokeh/issues/6152
If you’re knowledgeable about tornado applications, we’d appreciate any help. Otherwise, we appreciate your patience and are glad that you’re part of the Bokeh community.