phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'ca9863e93f7c7d755826c172f740cc02' 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 ('ca9863e93f7c7d755826c172f740cc02', -1, 1493592436, 1493592436, '36c6368c', -4, 0, 0)

Line : 187
File : sessions.php