Error delete user and message email

I want to thank you for your help, I have three queries:
1) When I want to delete a user delete when I get an error: “Fatal error: Call to undefined function array_column() in /home3/repairm/public_html/la18gamer.com/wp-content/themes/blackfyre/functions.php on line 3389”
2) Is possible that when creating a clan clan that automatically appear in the menu/clanes, because when I have to do it manually.?
3) How to change the message reaches the user’s mail when you forget the password because it comes as blackfire.

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