You are using illegal id-attributes(illegal before HTML5) inside the document, e.g. 2-slide . Fix them. To explain: to solve the known misbehaviour of element.querySelectorAll() the selector .slide will be internally rewritten(by using the id of the element). This will result in something like that: #2-slide .moreselectors …and forces the error, because an ID may not … Read more
You’re most likely using this on a local file over the file:// URI scheme, which cannot have cookies set. Put it on a local server so you can use http://localhost.
It means you’ve tried to insert a DOM node into a place in the DOM tree where it cannot go. The most common place I see this is on Safari which doesn’t allow the following: document.appendChild(document.createElement(‘div’)); Generally, this is just a mistake where this was actually intended: document.body.appendChild(document.createElement(‘div’)); Other causes seen in the wild (summarized … Read more