Error when trying to modify the widgets

Hi Kriesi support,
Our website http://www.salonghina.dk has the theme Enfold Version: 4.7.6.4 However when trying to access the footer through the Appearance > widgets I get this error message:

“Warning: Array to string conversion in /customers/f/8/b/salonghina.dk/httpd.www/wp-includes/block-editor.php on line 340 Fatal error: Uncaught TypeError: explode(): Argument #2 ($string) must be of type string, array given in /customers/f/8/b/salonghina.dk/httpd.www/wp-includes/class.wp-dependencies.php:186 Stack trace: #0 /customers/f/8/b/salonghina.dk/httpd.www/wp-includes/class.wp-dependencies.php(186): explode(‘?’, Array) #1 /customers/f/8/b/salonghina.dk/httpd.www/wp-includes/class.wp-styles.php(371): WP_Dependencies->all_deps(Array, false, false) #2 /customers/f/8/b/salonghina.dk/httpd.www/wp-includes/class.wp-dependencies.php(126): WP_Styles->all_deps(Array) #3 /customers/f/8/b/salonghina.dk/httpd.www/wp-includes/block-editor.php(347): WP_Dependencies->do_items(Array) #4 /customers/f/8/b/salonghina.dk/httpd.www/wp-includes/block-editor.php(479): _wp_get_iframed_editor_assets() #5 /customers/f/8/b/salonghina.dk/httpd.www/wp-admin/widgets-form-blocks.php(29): get_block_editor_settings(Array, Object(WP_Block_Editor_Context)) #6 /customers/f/8/b/salonghina.dk/httpd.www/wp-admin/widgets.php(32): require(‘/customers/f/8/…’) #7 {main} thrown in /customers/f/8/b/salonghina.dk/httpd.www/wp-includes/class.wp-dependencies.php on line 186
There has been a critical error on this website. Please check your site admin email inbox for instructions.”

I would appreciate if you can fix it, I have been trying for a long time without any improvement