Symptoms

The Appit wizards were extremely slow for me yesterday. Primarily I worked with the DocuSign wizards, but the problem was visible in all wizards. The slow down became very significant to where I could barely work. I tried closing the browser and clearing my cache, but that did not solve the problem. I took a short video when the problem started and the slowness only got worse. You'll notice a Null error in the video, too. I'm not sure what caused that, but it would happen periodically and I would have to close the designer and lose all of my work. I was using Firefox 42.0.
 

Diagnoses

This is a known issue with newer versions of Firefox.
 

Resolution

The slowness should disappear by using Private mode for Firefox.