I have an existing facebook app. I can search for it from the "search" box on the facebook site.
It used to resolve just fine. Now even though I still see the app in search results I get a 4oh4 error when clicking on the app link.
Everything else works just fine, the app works, the link to visit app from developer section works.
The id's are the same but the facebook search link seems to have slightly different URL.
The search I did was for ClubView
Plug a URL into the Bookmark URL field:
This is a bug logged with Facebook and that is the known workaround.
This one is very easy, your app is in sandbox mode that means only developers can see it, and if you are not logged as a developer it will show you 4oh4's error page. Your welcome! :)
I can see your app in the search results and click on it without issue. If you just recently submitted the app for search, then maybe the URL didn't have a chance to properly propagate to all of Facebook's servers.
来源：https://stackoverflow.com/questions/7352494/app-page-used-to-resolve-from-facebook-search-now-it-4oh4s