Ticket #48929: 48929.patch

src/wp-includes/class-wp-fatal-error-handler.php

@@ -183 +183 @@
                 if ( true === $handled && wp_is_recovery_mode() ) {
                         $message = __( 'There has been a critical error on this website, putting it in recovery mode. Please check the Themes and Plugins screens for more details. If you just installed or updated a theme or plugin, check the relevant page for that first.' );
                 } elseif ( is_protected_endpoint() ) {
-                        $message = __( 'There has been a critical error on this website. Please check your site admin email inbox for instructions.' );
+                        if ( is_multisite() ) {
+                                $message = __( 'There has been a critical error on this website. Please reach out to your site administrator, and inform them of this error for further assistance.' );
+                        } else {
+                                $message = __( 'There has been a critical error on this website. Please check your site admin email inbox for instructions.' );
+                        }
                 } else {
                         $message = __( 'There has been a critical error on this website.' );
                 }