Cannot read property 'hasOwnProperty' of undefined

The following code is supposed to be pasted in every page that uses amplitude:

(function(e,t){var n=e.amplitude||{_q:[],_iq:{}};var r=t.createElement("script");r.type="text/javascript"; r.async=true;r.src="https://d24n15hnbwhuhn.cloudfront.net/libs/amplitude-3.0.1-min.gz.js"; r.onload=function(){e.amplitude.runQueuedFunctions()};var i=t.getElementsByTagName("script")[0]; i.parentNode.insertBefore(r,i);function s(e,t){e.prototype[t]=function(){this._q.push([t].concat(Array.prototype.slice.call(arguments,0))); return this}}var o=function(){this._q=[];return this};var a=["add","append","clearAll","prepend","set","setOnce","unset"]; for(var u=0;u<a.length;u++){s(o,a[u])}n.Identify=o;var c=function(){this._q=[];return this; };var p=["setProductId","setQuantity","setPrice","setRevenueType","setEventProperties"]; for(var l=0;l<p.length;l++){s(c,p[l])}n.Revenue=c;var d=["init","logEvent","logRevenue","setUserId","setUserProperties","setOptOut","setVersionName","setDomain","setDeviceId","setGlobalUserProperties","identify","clearUserProperties","setGroup","logRevenueV2","regenerateDeviceId"]; function v(e){function t(t){e[t]=function(){e._q.push([t].concat(Array.prototype.slice.call(arguments,0))); }}for(var n=0;n<d.length;n++){t(d[n])}}v(n);n.getInstance=function(e){e=(!e||e.length===0?"$default_instance":e).toLowerCase(); if(!n._iq.hasOwnProperty(e)){n._iq[e]={_q:[]};v(n._iq[e])}return n._iq[e]};e.amplitude=n; })(window,document);

There is however this issue:

Cannot read property 'hasOwnProperty' of undefined

which can be found being called near the end of the amplitude code pasted above. If anyone else has run into this issue and knows how to solve it, any help would be appreciated.

[exAspArk]

Had the same issue, it was related to loading the script multiple times with turbolinks. I fixed it by wrapping the code with an “if” statement:

<script type="text/javascript">
  if (typeof amplitude === 'undefined') {
    (function(e,t){var n=e.amplitude||{_q:[],_iq:{}};...
     ...
  }
</script>

[sptaszek92]

I have the same problem. It looks like something’s happening asynchronously, because the error is not always showing up. Any suggestions?