Non-array argument in array_merge()-function [closed]

Just make sure it’s definitely an array before you try to merge it:

function minevalg_hent_innstillinger() {
    $defaults = array(); // define this somewhere; reference it here

    if ( is_array( $options = get_option( 'minevalg' ) ) )
        $options = array_merge( $defaults, $options );
    else
        $options = $defaults; 

    return $options;
}