JavaScript - Validacion formulario no funciona si lo cargo mediante link y la funcion load()

$("#menu a").click(function(e){

  var url = $(this).attr("href");

  $(".container-fluid").load(url , function(responseTxt, statusTxt, xhr){

    if(statusTxt == "error" && xhr.status == 404)

        $(this).html("<br><br><br><h1>Pagina no encontrada</h1>");

    });

    return false;

});

jquery.min.js:138 [En desuso] Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.

ajax @ jquery.min.js:138

Oa @ jquery.min.js:20

each @ jquery.min.js:33

domManip @ jquery.min.js:120

append @ jquery.min.js:113

html @ jquery.min.js:117

complete @ jquery.min.js:132

handleComplete @ jquery.min.js:143

w.onreadystatechange @ jquery.min.js:141

XMLHttpRequest.send (asincrónico)

ajax @ jquery.min.js:141

load @ jquery.min.js:132

(anónimo) @ (índice):97

handle @ jquery.min.js:63

o @ jquery.min.js:56

VM7289:84 Uncaught TypeError: Cannot read property 'addMethod' of undefined

    at HTMLDocument.<anonymous> (<anonymous>:84:20)

    at init.ready (jquery.min.js:26)

    at <anonymous>:1:13

    at Function.globalEval (jquery.min.js:32)

    at Function.httpData (jquery.min.js:144)

    at XMLHttpRequest.w.onreadystatechange (jquery.min.js:140)

    at Function.ajax (jquery.min.js:141)

    at HTMLScriptElement.Oa (jquery.min.js:20)

    at Function.each (jquery.min.js:33)

    at init.domManip (jquery.min.js:120)