phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '1fa5f87020eea3e200876c8f61ce802c' for key 1

INSERT INTO phpbb2_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('1fa5f87020eea3e200876c8f61ce802c', -1, 1414291981, 1414291981, '36c55ef1', 2, 0, 0)

Line : 187
File : sessions.php