The Divi theme has been known to cause some problems with the LiveEditor operation including the loading of options dialog boxes or popups
To fix this, you should go to OptimizePress > Support >Disable Styles and Scripts > Theme Styles and Scripts and check the 4 boxes there to stop some of the codes from the Divi theme affecting the OptimizePress LiveEditor
Divi Theme Patch
If you experience issues such as the following error when using the LiveEditor with a Divi site:
Fatal error: Call to undefined function et_is_ab_testing_active() ...
We have a patch which you can download from our repository - please ensure you remove any old version of this patch plugin first, then install the new plugin by going to Plugins > Add new and install and activate the plugin
https://github.com/OptimizePress/op-divi-fix (click download zip on this page to download the plugin)