Follow this case:

1. open first dialog (from link or button)
2. open second dialog (from button from previous dialog) and close first dialog via 'close' command
3. close second dialog (via closing button)
4. try open first dialog again and stack trace will occur saying "Uncaught TypeError: Cannot read property '_focusTabbable' of undefined"

Workaround: close first dialog first then open a new one.

Tested on: latest Chrome and Firefox

Code example:

<script>
$(function() { 

   $("#link_test1").on('click', function() {
     $("#test_dlg1").dialog('open');
   });

   $("#test_dlg2").dialog({
      autoOpen: false,
      modal: true
   });

   $("#test_dlg1").dialog({
      autoOpen: false,
      modal: true,
      buttons: [
    		{
          text: "open",
 	  click: function() {
            $('#test_dlg2').dialog("open");
            $(this).dialog("close");
    			}
    		}
        ]
   });

});
</script>

<a href="#" id="link_test1">open</a>

<div id="test_dlg1" title="test1">
test1
</div>

<div id="test_dlg2" title="test2">
test2
</div>

1. Go to ​http://jsbin.com/femiwafado/edit?html,js,output
2. Type say "abcde" in the text box

This results in errors in the console like this:

Uncaught ReferenceError: jQuery32101651943635009172_1493325192569 is not defined

Server side I have a simple PHP script which sleeps according to the length of the search term. So a shorter term like "ab" sleeps for 3 seconds and a longer term like "abcde" doesn't sleep at all. When you type "abcde", later requests will return earlier and this causes the error. Note that the callback parameter sent is the same for each request.

jquery version - 3.2.1 jquery ui - 1.12.1

server side PHP

<?php

$suggestions = '["aaaaaa","aaaaabb","aaabbbbb"]';

if (!empty($_REQUEST['term'])) {
    $delay = 6 - strlen($_REQUEST['term']);

    if ($delay > 0) {
        sleep($delay);
    }
}

if (!empty($_REQUEST['callback'])) {
    header('Content-Type: text/javascript');
    print $_REQUEST['callback'] . '(' . $suggestions . ')';
} else {
    header('Content-Type: application/json');
    print $suggestions;
}

The jqueryui position plugin describes itself in this way:

"This is a standalone jQuery plugin and has no dependencies on other jQuery UI components."

While it's true that it doesn't depend on other jQuery UI components, it does seem to depend on the base jqueryui.js file being included, but only for the "$.ui" namespace to exist. If you don't include jqueryui then it crashes on line 318 of position.js:

​https://github.com/jquery/jquery-ui/blob/master/ui/position.js#L317

For people like me who want the functionality in this plugin but don't otherwise need the code in jqueryui, this can be quite frustrating.

Apologies for not posting a jsfiddle, but I was unable to find a CDN that had a recent version of the standalone position.js file.