I have a facebook page tab where i try to get the access token with the link
https://www.facebook.com/dialog/oauth?client_id=[APP_ID]&redirect_uri=[REDIRECT_URI]
I has been working, but now all of a sudden I just get a generic error message: "An error occurred. Please try again later."
I have checked and the APP_ID is correct, and as far as i can see the applications settings are ok. Have there been any new changes to this or something?
This error message appears when the urls in the settings do not match the page you're trying to login from.
In the app settings you need to make sure that all urls share the same domain, also, if you have other domains which are different (sub domains, it's not possible with completely different urls) then add them in the "App Domain" field in the settings page.
Make sure that the redirect_uri also is of the same domain as the what you have in your application settings.
Another reason that might cause it is that maybe your app is on "sandbox mode".
There are plenty of questions about this problem: