跑模型时出现…op_level_cost_estimator. cc:689] Error in PredictCost() for the op:

712517: W tensorflow/core/grappler/costs/op_level_cost_estimator. cc:689] Error in PredictCost() for the op: op: "Softmax" attr { key: "T" value { type: DT_FLOAT } } inputs { dtype: DT_FLOAT shape { unknown_rank: true } } device { type: "CPU" vendor: "AuthenticAMD" model: "240" frequency: 3294 num_cores: 16 environment { key: "cpu_instruction_set" value: "SSE, SSE2" } environment { key: "eigen" value: "3.4.90" } l1_cache_size: 32768 l2_cache_size: 524288 l3_cache_size: 16777216 memory_size: 268435456 } outputs { dtype: DT_FLOAT shape { unknown_rank: true } }

用tensorflow搭了个CNN-BiGRU-Attention，加入Attention后训练模型时就会出现这样的提示，但还可以正常跑
这个提示我不太理解问题出在哪里
查不到解决办法，想问下有出现过类似问题的吗