关于PAI问题

在拖入源数据模块，缺失值填充模块后，拆分模块后，按照文档设置好参数，运行后，报错。
[font='Helvetica Neue', Helvetica, tahoma, Arial, 'Lantinghei SC', 'Hiragino Sans GB', STHeitiSC-Light, 'Microsoft YaHei', 微软雅黑]3] Instance 20160526142822504g7zpeam2 Failed.
[3] FAILED: Failed 2016052622283003ccfd94_6d2f_4c5b_8731_a0ee4d256f01:ODPS-1202005:Algo Job Failed-Algo Error-Invalid Column[user_id], all of this column's value is NULL
[3] Execute Odpscmd Failed!
[3] [2016-05-26 22:29:46] ERROR: run subjob: #3[odpscmd] failed!


这是怎么回事？