I keep on getting this error on updating a user:
PHP Warning: Cannot modify header information - headers already sent by (output started at /wp-admin/includes/update.php:134) in /wp-includes/pluggable.php on line 866, referer: /wp-admin/user-edit.php?user_id=4&wp_http_referer=%2Fwp-admin%2Fusers.php
Any ideas why?
My header.php does not seem to start with an empty space, but just with
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
And, besides, this seems to be more backend related...
update.php or one of the user edit files got corrupted. After the upgrade to 3.3.2 all good again. All users can be updated again within getting stuck in error reports.