phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '1706ccbb4aa5f23f02b88322f02c15c6' 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 ('1706ccbb4aa5f23f02b88322f02c15c6', -1, 1490535068, 1490535068, '36d3008e', -1000, 0, 0)

Line : 187
File : sessions.php