phpBB : Kritischer Fehler

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 'session_user_id'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, is_robot, session_admin) VALUES ('90c7621712fc38c9dd07ea490f1d929d', -1, 1519225724, 1519225724, '36a71dd0', 9, 0, '0', 0)

Line : 190
File : sessions.php