I am having this problem in Ipad Safari browser. It works fine on desktop safari, Chrome and Firefox.
On any example on developer.linkedinlabs.com/jsapi-console, when I click on "Signin with LinkedIn" button, it opens a new tab. This tab shows the title "Processing" and then hangs.
If I move to another tab and reactivate the "hanging" tab, it then works and brings up the linkedIn "login" window.
I have the same problem in my app. Hoping someone can help how to resolve this.
Thanks