Clicking Add Product brings up the new window, but the screen is locked with a spinning wheel that never goes away. ### Preconditions <!--- Provide a more detailed information of environment you use --> <!--- Magento version, tag, HEAD, etc., PHP & MySQL version, etc.. --> 1. v2.1.1 2. Php 5.6 ### Steps to reproduce <!--- Provide a set of unambiguous steps to reproduce this bug include code, if relevant --> 1. Update from 2.0.x to 2.1.1 2. Go to Catalog and create a new product ### Expected result <!--- Tell us what should happen --> 1. Editable screen ### Actual result <!--- Tell us what happens instead --> 1. Spinning wheel, following console error. `Uncaught TypeError: Cannot read property 'replace' of null import-handler.js:140` 