Title: Plugin Activation Error
Last modified: August 18, 2016

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# Plugin Activation Error

 *  [ch0de](https://wordpress.org/support/users/ch0de/)
 * (@ch0de)
 * [20 years, 5 months ago](https://wordpress.org/support/topic/plugin-activation-error/)
 * Every time I activate a plugin, this error pops up:
 * Warning: Invalid argument supplied for foreach() in /home/httpd/vhosts/ch0de.
   freedomsnet.net/httpdocs/wp-admin/upgrade-functions.php on line 504
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/httpd/vhosts/ch0de.freedomsnet.net/httpdocs/wp-admin/upgrade-functions.
   php:504) in /home/httpd/vhosts/ch0de.freedomsnet.net/httpdocs/wp-admin/admin.
   php on line 10
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/httpd/vhosts/ch0de.freedomsnet.net/httpdocs/wp-admin/upgrade-functions.
   php:504) in /home/httpd/vhosts/ch0de.freedomsnet.net/httpdocs/wp-admin/admin.
   php on line 11
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/httpd/vhosts/ch0de.freedomsnet.net/httpdocs/wp-admin/upgrade-functions.
   php:504) in /home/httpd/vhosts/ch0de.freedomsnet.net/httpdocs/wp-admin/admin.
   php on line 12
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/httpd/vhosts/ch0de.freedomsnet.net/httpdocs/wp-admin/upgrade-functions.
   php:504) in /home/httpd/vhosts/ch0de.freedomsnet.net/httpdocs/wp-admin/admin.
   php on line 13
 * Whats wrong? Im running 1.5 and it happens to almost all plugins.

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

 *  [Mark (podz)](https://wordpress.org/support/users/podz/)
 * (@podz)
 * [20 years, 5 months ago](https://wordpress.org/support/topic/plugin-activation-error/#post-276060)
 * And what did you do just before this started happening ?
 *  Thread Starter [ch0de](https://wordpress.org/support/users/ch0de/)
 * (@ch0de)
 * [20 years, 5 months ago](https://wordpress.org/support/topic/plugin-activation-error/#post-276061)
 * Nothing. I installed FeedWordpress and replaced rss-functions.php, but I replaced
   it back with the WP 1.5.2 one and still I get errors. I replaced admin.php and
   that other file.

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

The topic ‘Plugin Activation Error’ is closed to new replies.

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 2 replies
 * 2 participants
 * Last reply from: [ch0de](https://wordpress.org/support/users/ch0de/)
 * Last activity: [20 years, 5 months ago](https://wordpress.org/support/topic/plugin-activation-error/#post-276061)
 * Status: not resolved

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