phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '51b6fd7a3c41668f142f76313374e260' for key 'PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('51b6fd7a3c41668f142f76313374e260', -1, 1768404686, 1768404686, '2e251811', -4, 0, 0)

Line : 187
File : sessions.php