LinkedIn has recently updated their application requirements and needs additional information about your site if you are using the authentication features of JFBConnect for Joomla social networking. The JFBConnect - LinkedIn Application setup guide has already been updated with these new settings. However, if you configured your application before the last few weeks, it's likely your Application is incorrect and LinkedIn authentication may break in the future. Please take the time to follow the steps below to verify your LinkedIn Application settings and ensure authentication using JFBConnect will continue to operate smoothly.
The updated requirement is to properly configure your "OAuth 2.0 Redirect URLs" setting. If you've already configured Google+ authentication on your site, this step may be familiar to you. This setting lets LinkedIn know all of the valid URLs that a user can be redirected back to on your site. This enhances security of your application by preventing some attempts at 'hijacking' the authentication request.
The steps every Joomla site user with LinkedIn authentication using JFBConnect should take are:
Please note: That setting should be a comma-separated list and all be on one line without line breaks after each value/comma. It may be hard to read, but that's how LinkedIn's settings work.
As always, comments and feedback are welcome!