Sorry, I had to reset the testisite db, now your access is fixed
Thanks for looking into it
More precisely, the issue is into the CBSubs Content, wich is an internal CB plugin related to cbpaidsubsbot
I also did a test installation of a Helix template, wich uses megamenu too, and it works fine with CB: maybe you could compare their solution to investigate further and fix the issue (I would like to stick to T4)