Membership plugin - more tag issue

I have installed the Membership plugin and have got it working correctly... and love it! The only problem I am having is on the 'more tag' on the post, it shows as: "?']);" class="more-link">Continue reading ?" where it should only read "Continue reading ?"

I didn't have this issue when using another membership plugin (WP-Member) but I uninstalled it after having several issues with it last week.

Any ideas would be great. The functionality works OK, but it's unattractive and confusing to our readers.