Reset Facebook Cache

Problem: Facebook won't show the correct social media tile.

Solution: You can reset the FB cache here:

https://developers.facebook.com/tools/debug/?hc_location=ufi

Related: http://ogp.me/

Error: App Id Missing

developers.facebook.com is a valuable tool. I got the error, that the app id was missing. The solution is to create an app in the Facebook Developer. Use the id from the app in the markup, e.g.

 <meta property="fb:app_id" content="123456789012345">