How to fix a bug in wordpress?

Question

WordPress

The site was inherited
After updating the engine, the former admin does not enter the admin panel, just an empty page and an error appeared on the site that the login and password from the database are not correct, although the site itself works and when editing this data, the main error appears that the wrong data is entered, I with wordpress for the first time encountered where to dig?

Answer 1

Well, first of all, you need to look wp-config.php there in you will see access to the database, check the access.
Then enable WP_DEBUG :

Answer 2

1) rename the /wp-content/plugins folder to check for plugin conflicts
2) change the theme to default (without access to the admin panel, you can do this through the database)
2) enable wp-debug.php debug and look at the log
3) enable WP_ALLOW_REPAIR via wp-config.php and try to repair tables
https://www.maketecheasier.com/fix-corrupted-wordp...
4) check admin capabilities via DB (phpmyadmin)
5) try to update password via DB. generate a new password via md5 - www.miraclesalad.com/webtools/md5.php
and paste it into the required row of the wp_users table (for admin)