jQuery 3 will break display linking



So, instead, we’re experimentally defying the evolution of these methods and reverting to a simple, primordial model. This will break some code. If you have elements in a stylesheet that are set to display: none, the .show() method will no longer override that. So the most important rule for moving to jQuery 3.0 is this: Don’t use a stylesheet to set the default of display: none and then try to use .show() – or any method that shows elements, such as .slideDown() and .fadeIn() – to make it visible.