Title: Fatal error: Call to undefined method stdClass::add_query_var()
Last modified: August 21, 2016

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# Fatal error: Call to undefined method stdClass::add_query_var()

 *  Resolved [jon](https://wordpress.org/support/users/adiant/)
 * (@adiant)
 * [12 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-call-to-undefined-method-stdclassadd_query_var/)
 * “Fatal error: Call to undefined method stdClass::add_query_var() in …/wp-includes/
   taxonomy.php on line 356”
 * An Admin of an “under construction” web site is using one of my plugins, as well
   as a number of others, and started getting this error message right after she
   upgraded versions of WordPress, jonradio Multiple Themes and NextGen Gallery (
   NGG). The error remains when she deactivates all other plugins, but disappears
   if either NGG or my plugin is deactivated.
 * You’ll find more details in this thread:
    [http://wordpress.org/support/topic/updates-conflict-between-ngg-jonradion-multiple-themes-1](http://wordpress.org/support/topic/updates-conflict-between-ngg-jonradion-multiple-themes-1)
 * I’ve run out of ideas. And could really use some advice.

Viewing 2 replies - 1 through 2 (of 2 total)

 *  [fran330](https://wordpress.org/support/users/fran330/)
 * (@fran330)
 * [12 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-call-to-undefined-method-stdclassadd_query_var/#post-4739470)
 * I am the person. I just posted in the thrad mentionned by Mr Jonradio, that I
   found a solution. It’s not toally proper though and has its limits but it works.
 *  Thread Starter [jon](https://wordpress.org/support/users/adiant/)
 * (@adiant)
 * [12 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-call-to-undefined-method-stdclassadd_query_var/#post-4739639)
 * I’m still scratching my head over this one, but have it resolved, I think, with
   Version 4.8 of jonradio Multiple Themes. I delayed the interception of get_option‘
   stylesheet’ and ‘template’ calls until ‘plugins_loaded’ (Action hook).
 * I only observed the problem when Login was being attempted.

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘Fatal error: Call to undefined method stdClass::add_query_var()’ is closed
to new replies.

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 2 replies
 * 2 participants
 * Last reply from: [jon](https://wordpress.org/support/users/adiant/)
 * Last activity: [12 years, 1 month ago](https://wordpress.org/support/topic/fatal-error-call-to-undefined-method-stdclassadd_query_var/#post-4739639)
 * Status: resolved

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