Why has my Facebook application stopped working?

I have two applications with two canvas urls: 1. apps.facebook.co开发者_开发知识库m/walnuts-album 2. apps.facebook.com/walnuts

Today I updated the urls of the second one two reach my server (same urls as the first app), little after I changed it both of the apps stopped to work for new users (for me it's working but not for anyone else).

Anyone knows what is all about? (and how can I fix this).

https://developers.facebook.com/apps/APPID/advanced

There is Sandbox Mode. Turn it OFF, because in sandbox mode it'S only accessible for developers