Similar issue as rutgervdgr for me, I’m also seeing WSOD but in my case it is a fresh qtranslate-X install on WP4.1.1., not upgrading from z or mq.
When logged-in as admin, no issue, the page will display properly, but when logged out, white page. I tried disabling all other plugins / changing theme to 2013 with no result. If I disable qtranslate-X, website goes back to normal. Tried to enable debug, but nothing showed up… any idea?
Thanks for your help!