Recently, I was asked to debug one FBML Facebook app which was showing randomly this error. Usually, this error when it appears, does not always appear and not to all users.
Error while loading page from App Name.
"Empty Response Received".
While searching for the cause and possible solution, I stumbled upon these threads and I found there are too many users who are facing this issue since mid April. have a look at some of the threads people re complaining about this annoying and mysterious error.
http://forum.developers.facebook.net/viewtopic.php?id=96363
http://forum.developers.facebook.net/viewtopic.php?id=97082
Also check this bugs thread
This error is only occurring in the FBML Canvas apps. Since FB has stopped FBML based new apps, I suspect all FBML apps are experiencing this error which are built using old API. I checked our other apps we have built using Graph Auth API 2.0 and they don’t show this error at all.
It looks like the issue first appeared in the April/May and got worsened in June. & this all is FBML related.
It also appears that people who resolved the issue successfully, they got it done by switching to latest updated FB API.
Although I could not pin-point the cause of error in the problematic app, I did compare its settings in the app setting panel by setting up its home page with Graph API and compared its settings with those of which were developed with Graph API (oAuth 2.0) and which incidentally have never shown this “Empty Response Received” error. Take a look at the following screen shot of the settings.
UPDATE: Make sure you have removed all errors notices and warnings from your PHP scripts. Hide a ll errors if you already have not adding following at the top of your config file:
ini_set('display_errors', '0');
And needless to say that it’d be far better if you remove all your errors and warnings before hiding them.
Hope that helps.
Cheers!