Fatal error: Uncaught Error: Call to undefined function

Hey friends,
I have a big problem with my website as I am currently facing a White Screen of Death with my website. Can you please help me?

All of a sudden, I get this error message:

Fatal error: Uncaught Error: Call to undefined function wp_get_additional_image_sizes() in /var/www/vhosts/hosting147995.a2f72.netcup.net/httpdocs/wp-includes/media.php:889 Stack trace: #0 /var/www/vhosts/hosting147995.a2f72.netcup.net/httpdocs/wp-includes/block-editor.php(189): wp_get_registered_image_subsizes() #1 /var/www/vhosts/hosting147995.a2f72.netcup.net/httpdocs/wp-includes/class-wp-theme-json-resolver.php(297): get_default_block_editor_settings() #2 /var/www/vhosts/hosting147995.a2f72.netcup.net/httpdocs/wp-includes/class-wp-theme-json-resolver.php(561): WP_Theme_JSON_Resolver::get_theme_data() #3 /var/www/vhosts/hosting147995.a2f72.netcup.net/httpdocs/wp-includes/script-loader.php(3205): WP_Theme_JSON_Resolver::get_merged_data() #4 /var/www/vhosts/hosting147995.a2f72.netcup.net/httpdocs/wp-includes/script-loader.php(3401): {closure}() #5 /var/www/vhosts/hosting147995.a2f72.netcup.net/httpdocs/wp-includes/class-wp-hook.php(308): {closure}(”) #6 /var/www/vhosts/hosting147995.a2f72.netcup.net/httpdocs/wp-includes in?/var/www/vhosts/hosting147995.a2f72.netcup.net/httpdocs/wp-includes/media.php?on line?889

Ich really don’t know what to do anymore and would be very thankful for your support!

Thanks!
Lara

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