Your port 80 or port 241 can be blocked by raising CurlException 7. To check how to upload the sample file to your site. He will show an error.
In my case, I had a beta domain hosted on 000webhost.com. He recently blocked port 80, which caused the same error. When I moved my domain to another hosting, the problem was resolved.
Hope this helps.
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The solution to the problem is that (I think, although this has not been proven) to get an https connection, since I observe that php sdk does not work in an http connection. Look at my question here
====== YEAH! FINAL AND CORRECT RESPONSE TO THE LAST =======
This situation can only occur when cURL is disabled by your web host ( applicable for 100% of cases of a similar problem ). Your site will work correctly if cURL is installed. Usually the error received by users (if error handling is enabled) is
Fatal error: Uncaught CurlException: 7: couldn't connect to host thrown in /home/.../base_facebook.php on line ...
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