v2.0 error: cookie-notice/includes/settings.php on line 1166

Hello,
when I installed your v2.0 plug-in, the header of my website became a mess, with a very long empty space and this error:

Notice: Undefined index: general in /home/customer/www/xxx.com/public_html/wp-content/plugins/cookie-notice/includes/settings.php on line 1166

even in my dashboar I saw this message

I rolled back immediately and now its fine.

Theme OceanWP

website: francescolegrenzi.cOm