Xception: warning unhandled case: <class 'NoneType'>

Has anyone encountered this problem, could you help me answer it please?

File "/home/huang/tvm zl/python/tvm/relay/frontend/onnx.py,line2290,in from onnxop = self. convert operator(op name, inputs, attr, opset) File "/home/huang/tvm zl/python/tvm/relay/frontend/onnx.py"line 2387, in convert operatorsym = convert map[op name](inputs, attrs, self. params) File "/home/huang/tvm l/python/tvm/relay/frontend/onnx.py"line 1783,in impl vllscale = infer value simulated(inputs[2], params) .asnumpy() File “/home/huang/tvm zl/python/tvm/relay/frontend/onnx.py”,line 55, in infer value simulatedreturn g.infer value simulated(input val, params) File “/home/huang/tvm zl/python/tvm/relay/frontend/onnx.py”, line 2114, in infer value simulatedreturn self.visit(input val) data File “/home/huang/tvm zl/python/tvm/relay/expr functor.py”, line 76, in visitraise Exception("warning unhandled case: (0]"format(type(expr)))

Exception: warning unhandled case: <class ‘NoneType’> Segmentation fault (core dumped)