I'm trying to create a prototype of an original game for a friend of mine but am encountering issues with exporting a custom deck in the Deck Builder tool. When using the deck builder, initially everything works great (I'm able to drag and drop all the jpgs and format them to a reasonable size). However, when I try to export my finished deck, I click on the "Export" button but nothing happens. There's no dropdown menu asking me where I want to export the file, no reaction, nothing. The only thing that happens is that the "Export" button turns blue but immediately goes back to the normally grey color once I take my cursor off of it.

I opened the Logger and it seems like the error may have something to do with a file that's missing. You can see the error here: https://imgur.com/lCRfgtj

That error could just be a red herring, so here's some more details in case it helps:
-I'm a mac user running Mojave (10.14.6) on my 2017 Macbook Pro
-The Deck Builder tool is on version 2.3.0
-My deck is below the recommended 5000 by 5000 size
-All the jpgs I'm importing are already the same size
-I can save the deck just fine (both Save and Save As)

Thanks for the help!