Database Error!

Error: Field 'last_seen' doesn't have a default value
Query: INSERT INTO users (uid, password, ip_address, first_seen) VALUES ("5d1270440eaef0.50835606", "U4NbD0edTZ6WM93glzYC3WDwYycesFOa", "34.204.36.101", UNIX_TIMESTAMP())
File: /includes/database.class.php
Line: 98
Backtrace: