If you try to start Ghost and access the admin panel when the currently active theme is not present in the content/themes directory, the following error is thrown

The admin panel should function 100% without a theme present, so that you can change theme to one that is present. This is a regression.
The frontend should show the error "The currently active theme casper is missing.", this also appears to have lost some styling.
/ghost/ to change the themeAny ideas how to fix this without updating ghost? I've deleted a theme after trying it out and now I can't get to the admin panel.
Edit: Nevermind, as a temporary workaround you can rename another theme folder to the folder you deleted.
Wow. You can't access the admin panel on a fresh install if you delete the casper directory?! I've even re-uploaded the entire casper directory that I deleted from the server, and the darn thing won't stop throwing 500.
Edit: after putting casper back, you must restart.