请问下 Failed to initialize graph 可能是什么问题呢？

我编译好了，然后给的样例数据下载下来并且转换成二进制了，然后我执行：
python -m tf_euler \
--data_dir ppi \
--max_id 56944 --feature_idx 1 --feature_dim 50 --label_idx 0 --label_dim 121 \
--model graphsage_supervised --mode train

报错是 RuntimeError: Failed to initialize graph

请问下是什么原因呢？

Start by reproducing the `python -m tf_euler` training command with the converted `ppi` data and the reported options. No source file or test is named; done means identifying why graph initialization fails and documenting the required correction.

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