Title: problem while upgrading
Last modified: August 19, 2016

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# problem while upgrading

 *  [truwizard](https://wordpress.org/support/users/truwizard/)
 * (@truwizard)
 * [15 years, 8 months ago](https://wordpress.org/support/topic/problem-while-upgrading/)
 * My site [http://wizardspost.com/](http://wizardspost.com/) is WORKING but a strange
   problem has appeared.
    I was UPGRADING to wordpress latest version when it stalled(
   I think) On refreshing it gave the following messages:
 * Warning: call_user_func_array() [function.call-user-func-array]: First argument
   is expected to be a valid callback, ‘__return_zero’ was given in /home/wizard/
   public_html/wordpress/wp-includes/plugin.php on line 166
 * Fatal error: Call to undefined function is_multisite() in /home/wizard/public_html/
   wordpress/wp-login.php on line 85
 * Now I cannot login to my wp-admin.
    Can anyone suggest what I should do.

Viewing 5 replies - 1 through 5 (of 5 total)

 *  [Samuel B](https://wordpress.org/support/users/samboll/)
 * (@samboll)
 * [15 years, 8 months ago](https://wordpress.org/support/topic/problem-while-upgrading/#post-1608812)
 * looks like a plugin problem
    ftp to site or use host’s file manager to rename
   the `/plugins` folder this will deactivate the plugins and allow you to log in
   rename folder back to normal and activate plugins one by one until you find offender
 *  Thread Starter [truwizard](https://wordpress.org/support/users/truwizard/)
 * (@truwizard)
 * [15 years, 8 months ago](https://wordpress.org/support/topic/problem-while-upgrading/#post-1609010)
 * I went to public_html and tried changing Plugins folder in **wp-includes**. That
   made it give an additional error and the website too stopped opening.
    So, I 
   restored the original and at least the site started opening again but my problem
   of not being able to log in for dashboard
 * Please could you TRY OUT [http://wizardspost.com/wordpress/wp-login](http://wizardspost.com/wordpress/wp-login)
   to know
 *  [Rev. Voodoo](https://wordpress.org/support/users/rvoodoo/)
 * (@rvoodoo)
 * [15 years, 8 months ago](https://wordpress.org/support/topic/problem-while-upgrading/#post-1609011)
 * plugin folder is in wp-content, not wp-includes
 * you do not want to change this file: wp-includes/plugin.php
 * you want to rename the wp-content/plugins folder, this weill deactivate all plugins
 *  Thread Starter [truwizard](https://wordpress.org/support/users/truwizard/)
 * (@truwizard)
 * [15 years, 8 months ago](https://wordpress.org/support/topic/problem-while-upgrading/#post-1609013)
 * Ok, Thanks
    I did that but still shows the same error as ( wonder if there is
   time gap till it takes effect)
 * Warning: call_user_func_array() [function.call-user-func-array]: First argument
   is expected to be a valid callback, ‘__return_zero’ was given in /home/wizard/
   public_html/wordpress/wp-includes/plugin.php on line 166
 * Fatal error: Call to undefined function is_multisite() in /home/wizard/public_html/
   wordpress/wp-login.php on line 85
 * Any suggestions?
    I dont want to loose my work by reintalling the full wordpress
   from site
 *  Thread Starter [truwizard](https://wordpress.org/support/users/truwizard/)
 * (@truwizard)
 * [15 years, 8 months ago](https://wordpress.org/support/topic/problem-while-upgrading/#post-1609043)
 * I downloaded wordpress 3.0.1 and installed it.
 * Good result – The page loads and I can also login to [http://wizardspost.com/wordpress/wp-admin/](http://wizardspost.com/wordpress/wp-admin/)
   AND see my dashboard. All the links seem to work properly EXCEPT PLUGINS.
 * Bad Result – When I click on Plugins on the dashboard I get this error :
 * Not Found
 * The requested URL /wordpress/wp-admin/plugins.php was not found on this server.
 * Additionally, a 404 Not Found error was encountered while trying to use an Error
   Document to handle the request.
 * On checking the files I note that plugins.php is in wp-admin > includes and another
   one in wp-includes
 * Any suggestions what I should do? Incidentally, I had only ONE plugin active (
   adsense-delux.php)
    SAME result when I rename wp-content/plugins folder

Viewing 5 replies - 1 through 5 (of 5 total)

The topic ‘problem while upgrading’ is closed to new replies.

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 5 replies
 * 3 participants
 * Last reply from: [truwizard](https://wordpress.org/support/users/truwizard/)
 * Last activity: [15 years, 8 months ago](https://wordpress.org/support/topic/problem-while-upgrading/#post-1609043)
 * Status: not resolved

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