Can not train data 

[INFO] [Engine$] EngineWorkflow.train
[INFO] [Engine$] DataSource: com.actionml.DataSource@6ddd1c51
[INFO] [Engine$] Preparator: com.actionml.Preparator@1fb2eec
[INFO] [Engine$] AlgorithmList: List(com.actionml.URAlgorithm@3d104c9b)
[INFO] [Engine$] Data sanity check is on.
[Stage 0:>                                                          (0 + 0) / 4]

it stuck in stage 0 long time 