Rendering stuck on Upfront created theme

Hello. I created a custom theme based off of the uf-scribe theme using the Upfront builder installed on Jollygoodtest.com (support access granted). I've exported the theme and installed it with Upfront builder + core on another site elegantpermanentcosmetics.com (support access granted). I'd like to continue editing and customizing the theme on elegantpermanentcosmetics.com since that is the site that will be using it. However, whenever I try to open Upfront builder to edit the theme it stops rendering at 51% everytime. Upfront builder works perfectly fine with your themes (for example I installed Fixer) and there's no problem. This is a fresh WP install and I was having it stop at 51% on another domain with upfront builder. So I think it has something to do with the theme I created but I don't know where to start as all exports from Jollygoodtest.com are doing this, even though it works fine on jollygoodtest.com.

I appreciate any help. Thank you!