Plugin lIst not showing

Hi,
We run similar sites (clones), on one site the plugin list is not showing anymore. I tried to find answers, but I am not a developer. I tried common solutions as deactivating plugins, comparing to our other websites, copying working files from other sites to the not functioning site. It does not work.

From debug true I get:
Fatal error: Uncaught Error: Call to undefined function is_php_version_compatible() in /home/server/domains/domainname/public_html/wp-admin/includes/class-wp-plugins-list-table.php:765 Stack trace: #0 /home/server/domains/domainname/public_html/wp-admin/includes/class-wp-plugins-list-table.php(574): WP_Plugins_List_Table->single_row(Array) #1 /home/server/domains/domainname/public_html/wp-admin/includes/class-wp-list-table.php(1244): WP_Plugins_List_Table->display_rows() #2 /home/server/domains/domainname/public_html/wp-admin/includes/class-wp-list-table.php(1175): WP_List_Table->display_rows_or_placeholder() #3 /home/server/domains/domainname/public_html/wp-admin/plugins.php(619): WP_List_Table->display() #4 {main} thrown in /home/server/domains/domainname/public_html/wp-admin/includes/class-wp-plugins-list-table.php on line 765

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So I guess the plugin list is there, it is just not being fetched properly. I would appreciate if someone could shine a light on this and hopefully help with a solutions.

Much obliged, Rudolf

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