WordPress 4.0 update – now I can't login

Looking into that now. The error message is helpful.

Can you tell us which version of PHP you are using? That is usually important for this sort of error.

Thanks for your response Robert, how do I find that out what version of PHP I’m using?

We can skip that for now. Could you explain your update method? Did you click the update button on the dashboard or do it some other way?

Please look in the file at /wp-admin/includes/class-wp-list-table.php and do a text search for this phrase:

function get_column_info()

When you find it, copy that entire line and paste it here so that I can see if the file is at least correct.

I clicked the update via the dashboard.

You want me to locate /wp-admin/includes/class-wp-list-table.php via the FTP correct?

Yes can you find that file in FTP and open it and do a search?

Here you go…

*/
function get_column_info() {
if ( isset( $this->_column_headers ) )
return $this->_column_headers;

$columns = get_column_headers( $this->screen );
$hidden = get_hidden_columns( $this->screen );

$sortable_columns = $this->get_sortable_columns();
/**
* Filter the list table sortable columns for a specific screen.
*
* The dynamic portion of the hook name, $this->screen->id, refers
* to the ID of the current screen, usually a string.
*
* @since 3.5.0
*
* @param array $sortable_columns An array of sortable columns.
*/
$_sortable = apply_filters( “manage_{$this->screen->id}_sortable_columns”, $sortable_columns );
?

This confirms the upgrade failed. The list-table.php file is new but the class-wp-list-table.php file is the wrong version.

I would suggesting downloading the WordPress 4.0 package and copying the files by FTP. At the very least, I would delete the wp-admin directory and upload a fresh copy of all the files. If you think there might be other problems you could replace all of the files. Just remember to keep a copy of config.php and any other customizations.

Thanks. Seems to have worked, although I’ve reverted to the previous wordpress and when i try updating to 4.0 the same problem still arises.

Most likely you need to upgrade your PHP version on the server.