Problem with deprecation alerts

[LonsterMonster]

I enabled the log in the wp config as it helps me make sure everything is correct when installing stuff to my install of wp and installed the plugin to see how it was and got these deprecation errors

Deprecated: Constant FILTER_SANITIZE_STRING is deprecated in /home/u464391981/domains/contribucraft.com/public_html/wp-content/plugins/wp-multi-network/wp-multi-network/includes/classes/class-wp-ms-networks-admin.php on line 245

Deprecated: Constant FILTER_SANITIZE_STRING is deprecated in /home/u464391981/domains/contribucraft.com/public_html/wp-content/plugins/wp-multi-network/wp-multi-network/includes/classes/class-wp-ms-networks-list-table.php on line 55

Deprecated: Constant FILTER_SANITIZE_STRING is deprecated in /home/u464391981/domains/contribucraft.com/public_html/wp-content/plugins/wp-multi-network/wp-multi-network/includes/classes/class-wp-ms-networks-list-table.php on line 57

Deprecated: Constant FILTER_SANITIZE_STRING is deprecated in /home/u464391981/domains/contribucraft.com/public_html/wp-content/plugins/wp-multi-network/wp-multi-network/includes/classes/class-wp-ms-networks-list-table.php on line 59

Deprecated: Constant FILTER_SANITIZE_STRING is deprecated in /home/u464391981/domains/contribucraft.com/public_html/wp-content/plugins/wp-multi-network/wp-multi-network/includes/classes/class-wp-ms-networks-list-table.php on line 61

Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in /home/u464391981/domains/contribucraft.com/public_html/wp-content/plugins/wp-multi-network/wp-multi-network/includes/classes/class-wp-ms-networks-list-table.php on line 64

Deprecated: Constant FILTER_SANITIZE_STRING is deprecated in /home/u464391981/domains/contribucraft.com/public_html/wp-content/plugins/wp-multi-network/wp-multi-network/includes/classes/class-wp-ms-networks-admin.php on line 437

[SteelWagstaff]

FILTER_SANITIZE_STRING was deprecated as of PHP 8.1. The documentation recommends using htmlspecialchars() instead: https://www.php.net/manual/en/filter.filters.sanitize.php. See https://stackoverflow.com/a/69207369 for a discussion of other methods to achieve a similar outcome.