Just bought the latest version, the library is also installed but Im getting this when I try to add new questions to a survey:

Uncaught TypeError: Cannot read property 'apply' of undefined
at Object.CjSurveyApi.executeFunctionByName (cj.surveys.min.js:99)
at Object.beforeSerialize (cj.surveys.min.js:45)
at a.fn.init.e.fn.ajaxSubmit (jquery.form.min.js:11)
at Object.CjSurveyApi.submitAjaxForm (cj.surveys.min.js:36)
at HTMLAnchorElement.onclick (VM4253 index.php?option=com_communitysurveys&view=survey&layout=questions&id=9:205)
CjSurveyApi.executeFunctionByName @ cj.surveys.min.js:99
beforeSerialize @ cj.surveys.min.js:45
e.fn.ajaxSubmit @ jquery.form.min.js:11
CjSurveyApi.submitAjaxForm @ cj.surveys.min.js:36
onclick @ VM4253 index.php?option=com_communitysurveys&view=survey&layout=questions&id=9:205