It seems now if there is an incomplete / empty tab, the module breaks all the JS on the site.
I could not debug perfectly, but maybe this was the problematic part:
<div id="tabs-tabset" class="drupal-tabs js-hide"><div class="description"></div><ul class="clear-block"></ul></div> </div>
I added a try-catch block to make it more robust. It's not an elegant solution, maybe you have a better idea to fix this inside the .module function. But at least it makes the JS code secure in that way that it does not break other JS at the site.