[Fixed] Anvil editor error when rendering

What I’m trying to do:
Open a form from my app.

What I’ve tried and what’s not working:
Since yesterday the anvil editor breaks and displays an error “Something went wrong rendering this part of the anvil editor”.
I noticed bringing the window width to a smaller resolution fixes this, or at least allows me to open the “Design” tab, but bringing the width up again breaks the window.
I noticed some errors appear on the chrome console:

Sorry about that - we’ll get it fixed!

(As a quick fix - go to your roles and deselect Show In Toolbox. One or more of these roles is causing the blow up)