I have had an app for a long time now, there are a few hundred people who play it daily but I no longer actively do Facebook development.
Today I got a bunch of emails complaining it no longer works, sure enough it's just a blank page.
I don't want to rewrite anything and am looking for the bare minimum I can do to get things rolling.
I have no desire to upgrade my Facebook library. I use $facebook->require_login() which seems to be where the problem is.
It is an FBML app and viewing source shows that it has outputted the correct JavaScript redirect it just simply does nothing.
Previously I had turned a bunch of options off in the app settings to correct other problems created by constant updates but now it seems they no longer give that option.
https://github.com/facebook/php-sdk/blob/master/examples/example.php is about all you need to know.
I didn't upgrade some functionality (some fql queries etc) simple because they are not critical to the application although I don't think that would take much longer.
Less than an hour to get things rolling.