import paddle
a = paddle.ones([100])
a.stop_gradient = False
b = paddle.ones([100])
b.stop_gradient = False
c = a + b
d = c + c
e = d + d
# paddle_out_grads = paddle.autograd.backward([e], [paddle.ones([100])]) # rigth
paddle_out_grads = paddle.autograd.backward([e,c,d], [paddle.ones([100]),paddle.ones([100]),paddle.ones([100])])

Traceback (most recent call last):
  File "/host_home/wanghuan29/Paddle/test_grad.py", line 13, in <module>
    paddle_out_grads = paddle.autograd.backward([e,c,d], [paddle.ones([100]),paddle.ones([100]),paddle.ones([100])])
  File "/usr/local/lib/python3.9/dist-packages/decorator.py", line 232, in fun
    return caller(func, *(extras + args), **kw)
  File "/host_home/wanghuan29/Paddle2/build/python/paddle/base/wrapped_decorator.py", line 40, in __impl__
    return wrapped_func(*args, **kwargs)
  File "/host_home/wanghuan29/Paddle2/build/python/paddle/base/framework.py", line 726, in __impl__
    return func(*args, **kwargs)
  File "/host_home/wanghuan29/Paddle2/build/python/paddle/autograd/backward_mode.py", line 140, in backward
    core.eager.run_backward(tensors, grad_tensors, retain_graph)
SystemError: (Fatal) Unable to find next node in the GradTensorHolder 
Trying to run Node without configuring its GradTensorHolder.
  [Hint: Expected node_input_buffer_iter != node_input_buffers_dict.end(), but received node_input_buffer_iter == node_input_buffers_dict.end().] (at /host_home/wanghuan29/Paddle2/paddle/fluid/eager/backward.cc:272)

import paddle
a = paddle.ones([100])
a.stop_gradient = False
b = paddle.ones([100])
b.stop_gradient = False
c = a + b
d = c + c
e = d + d
f, g = paddle.split(e, num_or_sections=2, axis=0)
h = f + f
paddle_out_grads = paddle.autograd.backward([h,g], [paddle.ones([50]),paddle.ones([50])])