Okay, so many of you guys still ask me about how to fix these warning messages in our Facebook scripts. Today I’m going to give you two possible fixes that you can do. By the way, here’s the warning message we want to remove:
You can fix it by adding a session_start() on top of your PHP file, just right after your first line <?php tag. It looks like this:
You can fix it by moving the Facebook class and instance code on top of your PHP file. It would look like this:
If none of them worked, you can read more here.