arudd on "[Plugin: Menu Per Pages] Undefined offset: 0 Error"

Received this error in the select menu:
Notice: Undefined offset: 0 in /Applications/MAMP/htdocs/the-crucible-project/wp-content/plugins/menu-per-pages/includes/ddi_functions.php on line 20
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https://wordpress.org/plugins/menu-per-pages/