If you use Bokeh 2 then please check your version number in the about box. On Windows or Mac, start Bokeh 2 and open the Help menu (circle with a question mark on your Bokeh 2 toolbar) to find the about box.
Older versions use our old activation system which will stop working for Bokeh 2 on June 16th, 2012. Bokeh 2 won’t immediately die, but you won’t be able to do a new installation and activate it.
If Bokeh 2 is working for you then you don’t need to reinstall. But if it ever gives you any trouble (like activation errors) then uninstall the old version and run that new installer. Instructions for uninstalling are below.