This is caused by the STRICT_TRANS_TABLES
SQL mode defined in the
%PROGRAMDATA%\MySQL\MySQL Server 5.6\my.ini
file. Removing that setting and restarting MySQL should fix the problem.
If editing that file doesn’t fix the issue, see http://dev.mysql.com/doc/refman/5.6/en/option-files.html for other possible locations of config files.