Title: critical error when activating plugin
Last modified: July 14, 2020

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# critical error when activating plugin

 *  Resolved [zaesar](https://wordpress.org/support/users/zaesar/)
 * (@zaesar)
 * [5 years, 10 months ago](https://wordpress.org/support/topic/critical-error-when-activating-plugin/)
 * Hi Justin,
 * I just downloaded the plugin on a subsite and when activating I get a critial
   error when debugging:
 * `Fatal error: Uncaught Error: Call to undefined function get_blog_option() in/
   home/stokedno/channels.example.com/wp-content/plugins/network-subsite-user-registration/
   includes/settings.php:111 Stack trace: #0 /home/stokedno/channels.example.com/
   wp-content/plugins/network-subsite-user-registration/includes/settings.php(226):
   NSUR_Settings::get_instance() #1 /home/stokedno/channels.example.com/wp-content/
   plugins/network-subsite-user-registration/network-subsite-user-registration.php(
   147): require_once('/home/stokedno/...') #2 /home/stokedno/channels.example.com/
   wp-includes/class-wp-hook.php(287): NSUR->includes('') #3 /home/stokedno/channels.
   example.com/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(NULL, 
   Array) #4 /home/stokedno/channels.example.com/wp-includes/plugin.php(478): WP_Hook-
   >do_action(Array) #5 /home/stokedno/channels.example.com/wp-admin/includes/menu.
   php(155): do_action('admin_menu', '') #6 /home/stokedno/channels.example.com/
   wp-admin/menu.php(326): require_o in /home/stokedno/channels.example.com/wp-content/
   plugins/network-subsite-user-registration/includes/settings.php on line 111`
 * Can’t figure out what is wrong…
 * Thanks for your time
    -  This topic was modified 5 years, 10 months ago by [zaesar](https://wordpress.org/support/users/zaesar/).

Viewing 6 replies - 1 through 6 (of 6 total)

 *  Thread Starter [zaesar](https://wordpress.org/support/users/zaesar/)
 * (@zaesar)
 * [5 years, 10 months ago](https://wordpress.org/support/topic/critical-error-when-activating-plugin/#post-13120076)
 * To give a better understanding of my site and subsites I’ll explaining here a
   bit more.
 * I have a main site that is a membershipside (paidmembershipspro plugin). Users
   can create their profile and post diferent things. The subsites: channels and
   products. Will be a place where to upload like courses (something like patreon)
   where people can register to courses done by my members (learndash plugin with
   wisdmlabs). The other subsite is a page where they will be able to sell products(
   something like ebay) with vendors plugin.
 *  Plugin Author [Justin Fletcher](https://wordpress.org/support/users/justinticktock/)
 * (@justinticktock)
 * [5 years, 10 months ago](https://wordpress.org/support/topic/critical-error-when-activating-plugin/#post-13120776)
 * just to confirm you are running NSUR version 2.9 ?
 *  Thread Starter [zaesar](https://wordpress.org/support/users/zaesar/)
 * (@zaesar)
 * [5 years, 10 months ago](https://wordpress.org/support/topic/critical-error-when-activating-plugin/#post-13121074)
 * Yep,
 * But as it seems it needs to be a multisite (?)
 * Now I’m a bit confused. I want to users to be able to share their login on the
   diferent subdomains but open individual wp-admin of each subdomain or domain.
 * Hope that this is even possible?
 * Appreciate your time
 *  Plugin Author [Justin Fletcher](https://wordpress.org/support/users/justinticktock/)
 * (@justinticktock)
 * [5 years, 10 months ago](https://wordpress.org/support/topic/critical-error-when-activating-plugin/#post-13121333)
 * yes it needs to be multi-site (e.g. a WP Network).. and that would be your issue
   as the function being called and giving an error is only available on Multisite.
 * if you are activating/installing on single installs for wordpress then you should
   have got a message saying something like “…this only works on multisite”, did
   you see anything on the admin side ?
 *  Thread Starter [zaesar](https://wordpress.org/support/users/zaesar/)
 * (@zaesar)
 * [5 years, 10 months ago](https://wordpress.org/support/topic/critical-error-when-activating-plugin/#post-13124854)
 * Thank you Justin
 *  Plugin Author [Justin Fletcher](https://wordpress.org/support/users/justinticktock/)
 * (@justinticktock)
 * [5 years, 10 months ago](https://wordpress.org/support/topic/critical-error-when-activating-plugin/#post-13125427)
 * I’m closing this ticket out now… come back if you chose to try WordPress Networks/
   Multi-site 🙂

Viewing 6 replies - 1 through 6 (of 6 total)

The topic ‘critical error when activating plugin’ is closed to new replies.

 * ![](https://ps.w.org/network-subsite-user-registration/assets/icon-256x256.png?
   rev=1612217)
 * [Network Subsite User Registration](https://wordpress.org/plugins/network-subsite-user-registration/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/network-subsite-user-registration/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/network-subsite-user-registration/)
 * [Active Topics](https://wordpress.org/support/plugin/network-subsite-user-registration/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/network-subsite-user-registration/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/network-subsite-user-registration/reviews/)

 * 6 replies
 * 2 participants
 * Last reply from: [Justin Fletcher](https://wordpress.org/support/users/justinticktock/)
 * Last activity: [5 years, 10 months ago](https://wordpress.org/support/topic/critical-error-when-activating-plugin/#post-13125427)
 * Status: resolved