I just found the same error! I cannot send messages to users with a dash in their username. The error I am getting is when I try to select that user as the recipient, it shows there name but then also the following errors IN the dropdown:
Warning: Cannot modify header information – headers already sent by (output started at /home/tr0421or/public_html/wordpress/wp-content/plugins/genesis-connect/lib/ajax.php:541) in /home/tr0421or/public_html/wordpress/wp-content/plugins/buddypress/bp-messages.php on line 556
Warning: Cannot modify header information – headers already sent by (output started at /home/tr0421or/public_html/wordpress/wp-content/plugins/genesis-connect/lib/ajax.php:541) in /home/tr0421or/public_html/wordpress/wp-content/plugins/buddypress/bp-messages.php on line 557
Warning: Cannot modify header information – headers already sent by (output started at /home/tr0421or/public_html/wordpress/wp-content/plugins/genesis-connect/lib/ajax.php:541) in /home/tr0421or/public_html/wordpress/wp-content/plugins/buddypress/bp-messages.php on line 558
I get the same error for other users but message will go thru.
are you using genesis connect by any chance? I have a post in to them about it…
