Error message when trying to use NEX forms

hello.

I recieve an error message when i press on the NEX plugin. Please advice what to do.

Please see text below for error message. thank you for your help!

fatal error: Uncaught Error: Cannot use object of type WP_Error as array in /home/carlnxru/public_html/wp-content/plugins/nex-forms/includes/classes/class.db.php:67 Stack trace: #0 /home/carlnxru/public_html/wp-content/plugins/nex-forms/includes/classes/class.dashboard.php(195): NEXForms_Database_Actions->checkout() #1 /home/carlnxru/public_html/wp-content/plugins/nex-forms/includes/classes/class.dashboard.php(163): NEXForms_dashboard->print_chart() #2 /home/carlnxru/public_html/wp-content/plugins/nex-forms/main.php(2207): NEXForms_dashboard->form_analytics() #3 /home/carlnxru/public_html/wp-includes/class-wp-hook.php(287): NEXForms_dashboard(”) #4 /home/carlnxru/public_html/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(”, Array) #5 /home/carlnxru/public_html/wp-includes/plugin.php(478): WP_Hook->do_action(Array) #6 /home/carlnxru/public_html/wp-admin/admin.php(254): do_action(‘toplevel_page_n…’) #7 {main} thrown in /home/carlnxru/public_html/wp-content/plugins/nex-forms/includes/classes/class.db.php on line 67
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