Upfront edit mode doesn't load

I've upgraded to the new version of Upfront, and from then on I can't edit my template.
Here's the error I get:

uncaught SyntaxError: Unexpected token ?j.template @ underscore.min.js:5Util.template @ upfront-util.js:20(anonymous function) @ uimage.js:1j.execCb @ require.js:1W.check @ require.js:1(anonymous function) @ require.js:1c @ require.js:1(anonymous function) @ require.js:1x @ require.js:1W.emit @ require.js:1W.check @ require.js:1(anonymous function) @ require.js:1c @ require.js:1(anonymous function) @ require.js:1x @ require.js:1W.emit @ require.js:1W.check @ require.js:1(anonymous function) @ require.js:1c @ require.js:1(anonymous function) @ require.js:1x @ require.js:1W.emit @ require.js:1W.check @ require.js:1W.enable @ require.js:1W.init @ require.js:1D @ require.js:1j.completeLoad @ require.js:1j.onScriptLoad @ require.js:1

Can you please help?
You have admin permissions, and I've already sent you the cPanel details via private message in the past (let me know if you need it again).

Thanks