[Bug] Unable to copy/paste templates

Hey Muralistas,

The app crashes when I try to copy/paste an unedited template.

Steps to reproduce:

1. Make new Mural with flowchart template

2. Attempt to copy/paste the template

3. Mural tries to save the change

Expected: It all works and I make beautiful flow charts 😍

Actual: The paste succeeds, fails to save and forces me to reload the page with no flow chart 😭