I am using version 22.214.171.124 of the membership plugin on a multi-site installation with buddypress.
I added 3 membership levels with no problem, but when I went to add a fourth level, I received the error message, "Cheatin 'uh."
Now when I visit the Access Levels Page, I see what looks like some broken HTML/CSS. And there is no longer an "Add New" button at the top of the page.
Happy to provide a screenshot if there is someway to attach one.