JQuery does not remove “dIsplay:hidden” at all

List of things I tried

• .removeClass and addClass
• show() and hide();
• changing the css

To begin: Yes, I do have onLoad in the beginning of my script, and all of the other components work perfectly. Yes, I have tried Googling, and nothing fixes the problem. This is not a dublicate.

$("button").click(function(){
  $("block").addClass("hidden"); //class hidden is display: none
  $("block").removeClass("hidden");
}

This is my code. No, block is not a class or ID, I am gonna use it as an example.
Please help, I do not know what I have done wrong in my code and why this doesn’t work.

By the way, adding the class works, removing it doesn’t.

HTML:

<block>A</block>