Classic Editor won’t load in WPBakery

I use WPBakery Page Builder 5.6 in WordPress 5.0.2.

I was not happy with the WPBakery pricing table so I downloaded Easy Pricing Tables 2.4.0.

All these versions are current at 21/12/2018.

I have a reproducible plugin conflict. When Easy Pricing Tables is Active WPBakery cannot load the “Backend editor” on some pages. Testing shows that this is because a problem loading the classic editor. There are three possible classic editors, WPBakery internal, Classic Editor Plugin, TinyMCE Advanced. These are all essentially the same code and I have tried all three with the same result failure to load.

Disabling Easy Pricing Tables and refreshing allows the classic editor to load.

I have debug turned on and there is no PHP error.
There is no error in the JavaScript console.