gentle9

I don′t know if this will help but I made a small video where you can see that it doesn′t work.
I forgot to show that when adding the plugin to the pagebuilder (not in the sidebar) it is working fine.
https://youtu.be/FczQ0Ps6c6s

Hm ok that is strange. I have installed a complete fresh new WordPress Installation without any other plugins or themes and still have this problem.

Wordpress Version: 4.6.1
Plugin Version: 1.2.1
Page Builder Version: 2.4.18
Theme: Tested with Twenty Sixteen and Twenty Fifteen and other themes.

Tested with Chrome Version 54.0.2840.99, Firefox Version 49.0.2 and Edge 38.14393.0.0 and always the same problem. Everything works only the Open Builder Button when added to Sidebar is not working.