major error after upgrading 4.6.1 –> 4.7.1

Internal server errors (error 500) are often caused by plugin or theme function conflicts, so if you have access to your admin panel, try deactivating all plugins. If you don’t have access to your admin panel, try manually resetting your plugins (no Dashboard access required). If that resolves the issue, reactivate each one individually until you find the cause.

If that does not resolve the issue, try switching to the default theme for your version of WordPress to rule-out a theme-specific issue. If you don’t have access to your admin panel, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel, navigate to /wp-content/themes/ and rename the directory of your currently active theme. This will force the default theme to activate and hopefully rule-out a theme-specific issue.

If that does not resolve the issue, it’s possible that a .htaccess rule could be the source of the problem. To check for this, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel, and rename the .htaccess file. If you can’t find a .htaccess file, make sure that you have set your SFTP or FTP client to view invisible files.

If you weren’t able to resolve the issue by either resetting your plugins and theme or renaming your .htaccess file, we may be able to help, but we’ll need a more detailed error message. Internal server errors are usually described in more detail in the server error log. If you have access to your server error log, generate the error again, note the date and time, then immediately check your server error log for any errors that occurred during that time period. If you don’t have access to your server error log, ask your hosting provider to look for you.

I deactivated all my plugins before I attempted the upgrade.

I renamed .htaccess and got the same error. I also removed some lines from it that were added by Wordfence and still nothing.

I then renamed my current theme’s folder, and it simply said “Theme not found” and that was it.

Here is my server error log:

[Mon Jan 23 03:30:28.774929 2017] [fcgid:warn] [pid 15634] [client 173.171.34.1:49610] mod_fcgid: stderr: PHP Fatal error: Cannot redeclare unregister_setting() (previously declared in /var/www/vhosts/zoldos.net/httpdocs/wp-includes/option.php:1939) in /var/www/vhosts/zoldos.net/httpdocs/wp-admin/includes/plugin.php on line 1808

– Try MANUALLY updating. Download a fresh copy of the WordPress .zip file to your computer, unzip it, and use that to copy up all files and folders EXCEPT the wp-config.php file and the /wp-content/ directory. You may need to delete the old wp-admin and wp-includes folders and files on your server before uploading the new ones. Please read the Manual Update directions first.
– Backup: If you haven’t already done, always backup everything (including your database) before doing any actions, just in case something really goes wrong. You can never have enough backups!

That’s exactly what I did, manual upgrade. I deleted all files according to the upgrade document, then uploaded the new files except wp-config.php and wp-content, etc., and it fried my site. ??

In case some files did not get installed properly, try manually RE-updating.

Okay got it. Thanks! Everything updated (plugins too), except for WP Foro forums. Still working on that. I appreciate your time! ??

You are welcome ??

In case some files did not get installed properly, try manually RE-updating