Warning: Undefined array key archive_sidebar

This error comes up when using the search button or when changing the amount of posts to display per page.

Full message:
“Warning: Undefined array key “archive_sidebar” in C:\xampp\htdocs\PSI\wp-content\themes\iknowledgebase\includes\template-functions.php on line 117″

Which is:
$sidebar = $iknowledgebase_settings[‘archive_sidebar’];

What do I need to do to get rid of this error?

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