Warning: hash_equals(): Expected user_string to be a string, null given when looking at a contact's profile via the front end
When looking at a contact's profile via the front end under Wordpress I get:
Warning: hash_equals(): Expected user_string to be a string, null given in /home/xxx/public_html/domain/wp-content/plugins/civicrm/civicrm/CRM/Contact/BAO/Contact/Utils.php on line 232.
I am on Wordpress 5.2.1 and CiviCRM 5.13.4. See also https://civicrm.stackexchange.com/questions/28768/hash-equals-expected-user-string-to-be-a-string-null-given-in-contact-bao-co.
Changing line 232 to the following:
if (!hash_equals((string)$check, (string)$inputCheck)) {
in the file: civicrm\civicrm\CRM\Contact\BAO\Contact\Utils.php fixed the problem.