平台ai studio cpu

# 开始训练100个pass
import pdb
for pass_id in range(10):
pdb.set_trace()
train_cost = exe.run(program=fluid.default_main_program(),
feed={'x': x_data, 'y': y_data},
fetch_list=[avg_cost])
print("Pass:%d, Cost:%0.5f" % (pass_id, train_cost[0]))

报错内容

----------------------
Error Message Summary:
----------------------
InvalidArgumentError: Sum operator should have at least one tensor
[Hint: Expected dtype != -1, but received dtype:-1 == -1:-1.] at (/paddle/paddle/fluid/operators/sum_op.cc:139)
[operator < sum > error]

这是版本错误吗