Fatal error: Call to undefined function wp()

Try manually resetting your plugins (no Dashboard access required). If that resolves the issue, reactivate each one individually until you find the cause.

If that does not resolve the issue, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel, navigate to /wp-content/themes/ and rename the directory of your currently active theme. This will force the default theme to activate and hopefully rule-out a theme-specific issue (theme functions can interfere like plugins).

I think you can try following options which could work in your case.

Option I :

If the error occurred after you installed any plugin recently ( e.g. sometime with WP-Super-Cache plugin), then delete the plugin either via your file manager in your cpanel (go to your domain folder, /wp-content/plugins), or via an ftp program.

Option II :

Sometime, this happens when people upgrade and sometimes in initial upload, files get corrupted, functions don’t call and it doesn’t all load up. So try to fresh upload the files except wp-content folder.

IMPORTANT : Make sure you backup wp-config.php file as it contains crucial info like database connection , etc.

Thanks

hi,
thanks for your reply
but the problem is that i’m not able to see the log in page also.

so, how could i make any possible changes???

In that case you can disable plugin from either through FTP or cPanel.

Just browse to /wp-content/plugins folder and rename plugins folder one-by-one ( this deactivates plugin ) and simultaneously try to access admin login page to check if it is restored back.

• This reply was modified 8 years, 3 months ago by Suwash.

I delated all pluge in, i updated worpress by ftp but the result is
mod_fcgid: stderr: PHP Fatal error: Call to undefined function wp() in /var/www/vhosts/cslgenova.com/httpdocs/wp-blog-header.php on line 16

??

If you still see that with all plugins gone, try forcing the default theme as detailed in the very first reply.