index-dark.html crashes dreamweaver

I have a decent macbook pro running dreamweaver 11.5, I have absolutely no problems editing any other HTML/CSS based websites but for some reason when I open index-dark.html (or any of the canvas templates) my dreamweaver becomes unresponsive for 30 seconds, and then finally unfreezes. Anytime I press save this happens again.

Its impossible to update a template - again, I have NO other issues editing other templates written in HTML/CSS/JS.

I tried disabling some of the JS on the page, I believe the issue is somehow linked to one of the CSS references.

This is very frustrating and impossible to edit a Canvas template.

i also have issues doing any work with canvas files in dreamweaver. Any change i make takes forever to save - and i just get the spinner loading and loading and loading. This became so frustrating that i use brackets instead to make changes to the canvas theme.

I get 3-4 pauses of 1 minute spinning ball in a row, eventually I can make code changes but as soon as I save, and have to make more changes it goes back to 3-4 pauses, each taking up to 1 minute for the spinning ball to stop.

This makes using this template useless for any practical sense of updating it.

I'm going to ask for a refund if this is not fixed, again it's a nice template but 100% unusable like this. Worse I told the client who paid for it they can use DreamWeaver to make small updates because they already own it. We spent months picking looking at templates and then selecting one.

Totally at a loss here.