print_header() was called more than once - this should not happen. Please check the code for this page closely. Note: error() and redirect() are now safe to call after print_header().
- line 2345 of lib/weblib.php: call to debugging()
- line 664 of lib/pagelib.php: call to print_header()
- line 90 of mod/chat/view.php: call to page_generic_activity->print_header(