I have been having the exact same issue for the last couple of days, well... I can't seem to edit anything. Tried a different browser, clearing my history, even tried to edit a duplicate,... nothing seems to work.
I made my main page a whole link to another page. Normally when I am editing, if I clicked on the main page it would go to the other one, now it just freezes up. I have to reload the page.
When I try to click 'EDIT' on any page, same thing happens, which is NOTHING.
When I try to add or edit snippets of code/images, again, same thing, freezes up and nothing happens.