SSD-Mobile net Auto-tune

Hi, I try auto tune ssd mobile net on arm cpu. After I get a log file, I try to compile the model but get a error:
File “…/tvm/python/tvm/relay/op/nn/_nn.py”, line 159, in schedule_conv2d
assert op is not None
TVMError: AssertionError

Anyone could give me some suggest, thanks.