I added this code to a router page today, an event handler for a hamburger menu container.
$w('#menuContainer1').onViewportEnter(function(event){
$w('#boxShuffle').collapse() // a standard container
})
Then all the Backend functions in my whole site stopped working. I fiddled with site history, and got it working again. Then I tried adding the same code another time and everything has stopped working for the second time.
Even deleting these lines of code doesn’t seem to help to fix my site now.