phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '0249dcc6f751dbc035d3e1d1e0781994' 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 ('0249dcc6f751dbc035d3e1d1e0781994', -1, 1481429238, 1481429238, '36a63003', 17, 0, 0)

Line : 187
File : sessions.php