Add Link dialogue box doesn't appear

My Link Dialogue box is not even visible on the Dashboard Panel so I am also unable to insert any links. I am also using ver:3.5.1
Any help would be most appreciated.

the recent updates on the plug-in UJI Countdown is the culprit for non appearance of the Add Link Dialogue box. its resolved for now.

I do not have the UJI Countdown plug-in installed. Only got Easy Digital Downloads plug-in installed and de-activated it and still no joy. I have also created a new user named “admin” and applied administrator rights and again still nothing happening.

Found the problem or rather a friend did for me. In the latest versions of wordpress the link manager is not included by default so you have to install it yourself.
Good Luck.

I have a similar problem with the “Add link” buttons after upgrading to 3.5.1. If I mark some text and the click “Add link”, nothing happens the first time. The second time, the dialogue box opens in the bottom left corner of the Edit Post page (below the browser window, so I have to scroll down to find it) and greys out the “Edit post” page. When I put a link in the form field and click “Add link”, the link is added, but the dialogue box doesn’t close. “Cancel” also doesn’t work. The only way to get back to editing the post is by loading another the page (e.g. clicking the back button) and then find my way back to the post I was editing. So I can add links, but it’s sort of irritating. (The problem appears consistently in both Visual and Text editor).

Updating all plugins seems to have solved the problem for me… Hope this info is useful to someone else.