Error on upgrade: Fatal error: Call to undefined function wpcf7_add_shortcode()

Mine too. Had to restore from a backup, delete 3.5.4 version plugin file, and recreate my forms on old plugin version. But would like to keep up to date. Any answers for us? Thanks.

@pharris324: If you require assistance then, as per the Forum Welcome, please post your own topic.

So it seems the plugin got deactivated after I did an upgrade. I was able to resolve this by manually activating the plugin through a php script – since I couldn’t do it through the admin.

Now, however, it is working but with my debugger on I am getting the following error message:

Warning: Missing argument 2 for wpcf7_add_shortcode() in ……/wp-content/plugins/contact-form-7/includes/shortcodes.php on line 179

Try deactivating other plugins and theme which extend Contact Form 7’s tag set. If it solves the issue, you need update of the extension plugin or theme.

This topic may be helpful.
https://www.ads-software.com/support/topic/after-update-undefined-function-wpcf7_add_shortcode

Hi, I had the same problem and found this workaround (thanks to emregan’s hint “it seems the plugin got deactivated”):
first remove the wpcf7_add_shortcode function from functions.php, upgrade contact form 7 and reactivate. Then you can put back the function and the shortcode works. (i’m on wordpress 4.0 and contact form 3.9.3