Warning: Invalid argument supplied for foreach() in /public_html/classes/Hook.php on line 491

[Kst]

Hello,

We got an error at the top of our page Warning: Invalid argument supplied for foreach() in /public_html/classes/Hook.php on line 491.

I've read that it could be a problem with the foreach loop or arrays, but I don't know php and don't have any idea how to fix it. 

In line 491 I find: foreach ($results as $result) {

Please help me with the problem, I am also attaching a picture of the code.