// ==UserScript==
// @name        Manjaro Forum auto-redirect to old site for missing pages
// @namespace   Manjaro Linux Forum
// @match       https://forum.manjaro.org/t/*
// @grant       none
// @version     1.0
// @author      SinTan
// @description 9/3/2020, 7:04:09 PM
// @downloadURL none
// ==/UserScript==
not_found=document.getElementsByClassName("page-not-found")
if(not_found)
  {
    error_msg=not_found[0].getElementsByClassName("title")[0].innerHTML
    if (error_msg=="Oops! That page doesn’t exist or is private.")
      {
        window.location.href=window.location.href.replace("://forum.","://archived.forum.")
      }
  }