Comment Section Is Broken

Any ideas on how to fix this?

I recently “upgraded” to the latest WordPress. It was a step by step (one WP version at a time) manual upgrade from 4.7 to 5.1. The comment section no longer works properly.

I have upgraded automatically to the latest, and it did not fix the problem.

If you comment, there are errors. The comment sticks, but the counter does not change and after submission of the comment, the posted sees this error message:

Warning: mysql_real_escape_string(): Access denied for user ”@’localhost’ (using password: NO) in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93

Warning: mysql_real_escape_string(): A link to the server could not be established in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93
Failed to query blacklist: ip – 47.137.192.152. Query: SELECT * FROM sk2_blacklist WHERE (value = ” AND (type = ‘ip_black’ OR type = ‘ip_white’)) AND score > 30 ORDER BY score DESC
SQL error: Access denied for user ”@’localhost’ (using password: NO)

Warning: mysql_real_escape_string(): Access denied for user ”@’localhost’ (using password: NO) in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93

Warning: mysql_real_escape_string(): A link to the server could not be established in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93
Failed to query blacklist: regex_content_match – Testing Comments.. Query: SELECT * FROM sk2_blacklist WHERE id IN(-1) AND score > 30 ORDER BY score DESC
SQL error: Access denied for user ”@’localhost’ (using password: NO)

Warning: mysql_real_escape_string(): Access denied for user ”@’localhost’ (using password: NO) in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93

Warning: mysql_real_escape_string(): A link to the server could not be established in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93

Warning: mysql_real_escape_string(): Access denied for user ”@’localhost’ (using password: NO) in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93

Warning: mysql_real_escape_string(): A link to the server could not be established in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93
Failed to insert blacklist entry: ip_white – 47.137.192.152.
SQL error: Access denied for user ”@’localhost’ (using password: NO)
Error: cannot update comment entry ID: 198760 to status: approved.
SQL error: Access denied for user ”@’localhost’ (using password: NO)

Warning: mysql_real_escape_string(): Access denied for user ”@’localhost’ (using password: NO) in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93

Warning: mysql_real_escape_string(): A link to the server could not be established in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93

Warning: mysql_real_escape_string(): Access denied for user ”@’localhost’ (using password: NO) in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93

Warning: mysql_real_escape_string(): A link to the server could not be established in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93

Warning: mysql_real_escape_string(): Access denied for user ”@’localhost’ (using password: NO) in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93

Warning: mysql_real_escape_string(): A link to the server could not be established in /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php on line 93
Failed inserting/updating sk2_kSpamTable record for comment ID:198760 (mode: overwrite).
Query: INSERT INTO yhgmsafl7_sk2_spams SET karma = 87.75,karma_cmts = ”, unlock_keys = ”, remaining_attempts = ”, last_mod = NOW(), comment_ID = 198760
SQL error: Access denied for user ”@’localhost’ (using password: NO)

Warning: Cannot modify header information – headers already sent by (output started at /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php:93) in /home/MYDIRECTORY/public_html/wp-includes/comment.php on line 548

Warning: Cannot modify header information – headers already sent by (output started at /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php:93) in /home/MYDIRECTORY/public_html/wp-includes/comment.php on line 549

Warning: Cannot modify header information – headers already sent by (output started at /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php:93) in /home/MYDIRECTORY/public_html/wp-includes/comment.php on line 550

Warning: Cannot modify header information – headers already sent by (output started at /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php:93) in /home/MYDIRECTORY/public_html/wp-includes/pluggable.php on line 1251

Warning: Cannot modify header information – headers already sent by (output started at /home/MYDIRECTORY/public_html/wp-content/plugins/SK2/sk2_functions.php:93) in /home/MYDIRECTORY/public_html/wp-includes/pluggable.php on line 1254