On edit post, Ajax is not working

I’m using a 3.5.1 installation for one of my client with ACF version 4.1.6 – the latest one.

We’ve already filed the problem in StackExcahnge.com in THIS THREAD.

But for reference, I’m saying it again:
I am using the plugin: Advanced Custom Fields. For several more images, I used it to add images using the image input field.

Now, when I edit a post, I can’t edit/add new image into the image field using the plugin. Using Firebug, it shows a js error:

Uncaught ReferenceError: tb_show is not defined

But the same fields work, when I add a new image using those fields.

Even the default WordPress editor is not working. Not even any AJAX in this page. ??

But I admire the plugin for its good support in all other sites I made for my client with a good respect to the sayings: Code is Poetry.

Thanks in advance to the author.

https://www.ads-software.com/extend/plugins/advanced-custom-fields/