WordPress Quick Edit is not Working

I didn’t do anything, but the “quick edit” menu was suddenly no longer working. I disabled all plugins and changed theme to default one, it still didn’t work. I thought maybe the problem was JavaScript, but I didn’t know how to fix it. I googled, and I found the solution. though this solution was not created for my problem, it worked. Below is it.

Add this line to wp-config.php:

define('CONCATENATE_SCRIPTS', false);

The original: http://wordpress.org/support/topic/cannot-edit-postsadd-new-posts-or-pages-js-not-working-correctly

But, not end…

After I added the code to wp-config.php, widgets can not be dragged, so are menus. I am finding the solution, again.