phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '1188642d8f46d0ebf916e3ea36aafba9' 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 ('1188642d8f46d0ebf916e3ea36aafba9', -1, 1513121275, 1513121275, '36a72c20', 15, 0, 0)

Line : 187
File : sessions.php