Wordpress 4.9.1 Update Caused A 500 Server Error

My All Wordpress Websites Encounter Error After New Wordpress 4.9.1 - Two Days Ago My All Websites Created With Websites Created With Wordpress Shows "HTTP ERROR 500". I Switched Automatic Wordpress Update For All Websites. I Think It's An Updated Caused Error Encountered On All My Websites. All Websites Hosted In Hostgator India. The Hostgator Support Team Only Find Or Shows Error Logs Only. Not Giving A Resolving Solution For It.

Please Refer Pasted Logs In Below Link And Give Me Resolving Solution For It ...

Http://support-tools.com/?c9734c82a5a8f531#avwjpgpwsbetuz95mi3znip+8g2efe+8vwqtunhe0ik=

Error Log - [25-Dec-2017 15:53:56 UTC] PHP Fatal error: Call to undefined function wp_queue_posts_for_term_meta_lazyload() in /home/indexris/public_html/wp-includes/class-wp-query.php on line 3002]

 

I think this should be an issue with the hosting side.

 

Another error finding log from the hosting provider side from my other websites ... They not giving accurate problem resolving the issue ...

[26-Dec-2017 02:20:34 UTC] PHP Fatal error: require(): Failed opening required '/home/indexris/riseprop.com/wp-includes/post.php' (include_path='.:/opt/alt/php56/usr/share/pear:/opt/alt/php56/usr/share/php') in /home/indexris/riseprop.com/wp-settings.php on line 166 [26-Dec-2017 03:18:07 UTC] PHP Warning: require(/home/indexris/riseprop.com/wp-includes/post.php): failed to open stream: No such file or directory in /home/indexris/riseprop.com/wp-settings.php on line 166 [26-Dec-2017 03:18:07 UTC] PHP Warning: require(/home/indexris/riseprop.com/wp-includes/post.php): failed to open stream: No such file or directory in /home/indexris/riseprop.com/wp-settings.php on line 166

 

The error is likely caused by your template or any plugins which is used to enhance your template functionality.

After reading your error log, I would trace any function which is related with 'Lazy Load' functionality. I think your template or plugin created 'a call' (via db or file) with already deprecated or less secure method.

Here are few things to help you solve the problem:

1. If it is possible, open your theme Panel. If there is menu to enable lazy load, turn it off immediately. If the menu lies in plugin, disable that specified plugin and try to load your site. If it fails,
2. Change to another template (try standard template which come with wordpress). You could change your theme via admin dashboard or FTP (file manager). If it solve the problem, it is likely your theme need to be updated. If the problem persist, disable the plugins.
3. Disable plugin one by one. Do this after you have changed template. Hint: I would start with plugin which offer 'lazy load' functionality.
4. Use latest PHP (ver 7.0/7.1 and up - when I write this post it is already latest version). I always use latest PHP in my server to minimize problem. If you use older PHP, try using latest version. You have to consider one thing while changing PHP: did my theme and plugins were designed to use the latest version? If the answer is yes, switch to latest PHP. If not, try another template and switch to another plugins which are compatible with latest PHP.

That are few suggestions I could write at the moment. I could write more suggestion but it is really hard to type using mobile phone.

Try few things I mentioned above and if it still didnt solve your problem, you could write few things about:

1. Template used in your site. 'News theme by xxx' or ...
2. What is your webserver? Each webserver have different and special configuration to work with latest wordpress update. Did you use NginX, Apache, Node.js, or Lighttpd.
3. Tell us about your Server Side Scripting used in your site. PHP 5.3, 5.4, 5.6, 5.x, 7.x or...
4. You could also describe your PHP configuration such as Max_execution_time, Memory_limit, Max_upload_size, etc.
5. If you use special configuration such as running Apache behind NginX, you could also tell us about it.

Just like you, few of my old site return http error 5xx due to incompatibility with older template and plugins. It seems my template and plugins were using an old method to call a function using less secure method. After updating the function with latest method (replacing some codes. Most of them are related with 'calling database' function with new and secure method) and the sites work as expected.

What I would like to say is: Upgrading WordPress is always a good idea. However, outdated script or less secure function which are used in plugins or few themes may not working as expected. Some template may produce errors and few of them may stop working completelly. To overcome such situation we could switch to standard template which come with WordPress setup while fixing the problem in older template and plugins.

Edit: I have just read your latest log (posted when I wrote this post), and your site using PHP 5.6 and recent log error is about file not available or inaccesible for unknown reasons (could be permission error or function error or most likely template or plugins make a request/call to wrong location)

 

Many thanks to all participants who responded my issue with great helping mind. At last, I found that it’s not WordPress newly Upgraded issue. It’s non-upgraded issue encountered with the WordPress. I am updating my website one by one they return to online. But some themes not supported by the new WordPress 4.9.1 security update.

 

Glad the issue has been resolved.
I am sure this thread would help anyone that have similar problem.

 

be sure to desactive any cache plugin before update.. and check that disk space and memory limit doesnt reach the limit

or try manual update.