Wordpress "Add new tag" button is not working

Question

I really dont know where else to look at :(

When I try to create a new tag in wordpress from back end under post column, it wont save the tag. However when I tried to save a blank it prompts me an error as suppose to be..only major issue is- it is not SAVING AT ALL.

Following are the things I tried with no luck -

• Deactivated all plugins(although I have only 3 plugin though) and then checked but no luck.
• Firebug it for JS errors but NO JS errors though.
• I freshly re-installed/updated Wordpress core files to look if it missed something previously but no luck.
• Tried by setting it to true for error but no luck define('WP_DEBUG', false);

Let me know what else I can try apart from these things.

FYI - I am testing the site on staging server so have URL something like this-

http://1XX.1XX.2XX.2XX:8XXX/

and this is what I set under WordPress Address (URL) & Site Address (URL) [although not very sure if this is actually has to do something with this or not]

Answer 1

I've had similar problem, maybe it's not js issue, but XML instead. Check if there are white spaces at end of the files involved ( after the PHP closing tag "?>") Hope it helps!

UPDATE

maybe ajax cross domain issue ( 307 Temporary Redirect ) last chance: Set this entries on your .htaccess file

SetEnvIf Origin "^http(s)?://(.+\.)?(abc\.com)$" origin_is=$0 
Header always set Access-Control-Allow-Origin %{origin_is}e env=origin_is

replace abc\.com with your actual domain. For eg: (google\.com)