NLP自学习平台为什么同一份文本分类的样本数据，换长文本分类模型，一直在训练中呢？

NLP自学习平台为什么同一份文本分类的样本数据，换长文本分类模型，一直在训练中呢？

tensorflow.python.framework.errors_impl.InvalidArgumentError: ValueError: `generator` yielded an element of shape (0,) where an element of shape (None, None) was expected.
Traceback (most recent call last):
  File \"/usr/local/lib/python3.6/dist-packages/tensorflow_core/python/ops/script_ops.py\", line 236, in __call__
    ret = func(*args)
  File \"/usr/local/lib/python3.6/dist-packages/tensorflow_core/python/data/ops/dataset_ops.py\", line 825, in generator_py_func
    \"of shape %s was expected.\" % (ret_array.shape, expected_shape))
ValueError: `generator` yielded an element of shape (0,) where an element of shape (None, None) was expected.