Getting notices when going to customizer

Hi I am getting, the notices bellow when I go to Customizer:
Notice: Undefined index: fontresizer_widget in public_html/wp-includes/class-wp-customize-widgets.php on line 510

Notice: Undefined index: fontresizer_widget in public_html/wp-includes/class-wp-customize-widgets.php on line 519

Notice: Undefined index: fontresizer_widget in public_html/wp-includes/class-wp-customize-widgets.php on line 520

Notice: Undefined index: fontresizer_widget i/public_html/wp-includes/class-wp-customize-widgets.php on line 591

Here is even more info:
Font resizer widget is not appearing in Sidebar where it should be (only in customizer), but it’s appearing in WP admin -> Appearance -> widgets

Can you please advise?
Thanks

• This topic was modified 7 years, 4 months ago by Dejan Markovic.