[TYPO3-english] Re: Oops, an error occurred! $toolbarItem "shortcuts" must implement interface backend_toolbarItem

[Tom Warwick]

I had the same issue, the only workaround I found was downgrading my server to PHP 5.5

On a shared host, I placed this in my .htaccess

AddHandler application/x-httpd-php55 .php

I doubt this will get patched, I'd strongly recommend getting your site off the 4.X branch.