https://bugs.winehq.org/show_bug.cgi?id=37360
--- Comment #2 from mike@mbscott.me.uk --- Thank you you were right. I deleted and recreated my wine prefex then re-installed steam, and copied the Rocksmith 2014 app back under SteamApps\common and I no longer get the error.
Rocksmith 2014 still doesn't work, it immediately closes after briefly showing a white window, but this is a different issue.