Database Error!

Error: Field 'last_seen' doesn't have a default value
Query: INSERT INTO users (uid, password, ip_address, first_seen) VALUES ("5c968e2d84db58.71683847", "7HLCX3nujveNwH140oCoGcidvkvW1HZq", "18.206.168.65", UNIX_TIMESTAMP())
File: /includes/database.class.php
Line: 98
Backtrace: