# open website in `Content Mode`
# edit content any block and type this in it (view `Source` toolbar button in CKEditor): `aa <a class="cc" href="#" title="tt">link</a> bb`
# save content block
# edit that content block again and this time:
* click on the link
* right click on the link
* select `Edit Link` menu item
# confirm, that no JS error has happened at this point