Urgent: SalesIQ live chat JS and display errors

Dear Zoho-Support Team,

we have a problem with the Zoho SalesIQ Code-Snippet:

...var $zoho= $zoho || {salesiq:{values:{},ready:function(){$zoho.salesiq.floatbutton.visible("hide");}}};var d=document;s=d.createElement("script");s.type="text/javascript";s.defer=true;s.src=" https://salesiq.zoho.com/partcadgmbh/float.ls?embedname=partcadgmbh";t=d.getElementsByTagName("script")[0];t.parentNode.insertBefore(s,t);...

As on your support website suggested we have added the code snippet to the HEAD-Section of our website, but on the firebug console we always get the following error: NS_ERROR_NOT_AVAILABLE. Additionally the chat button isn't displayed correctly.

We do get the same errors on your very own support website: https://www.zoho.com/salesiq/help/getting-started-add-salesiq-code-to-website.html#addchat (please have a look at the attachments!).

Our system: Apple, Yosemite 10.10.5, Firefox: Version 43.01

Can you please solve this problem?