转换h5文件：
coreml_model = coremltools.converters.keras.convert('model.h5')
产生以下错误：
File ".../venv/lib/python2.7/site-
packages/coremltools/converters/keras/_keras_converter.py", line 722,
in convert
custom_conversion_functions=custom_conversion_functions)
File ".../venv/lib/python2.7/site-
packages/coremltools/converters/keras/_keras_converter.py", line 527,
in convertToSpec
custom_conversion_functions=custom_conversion_functions)
File ".../venv/lib/python2.7/site-
packages/coremltools/converters/keras/_keras2_converter.py", line 173,
in _convert
graph.build()
File ".../venv/lib/python2.7/site-
packages/coremltools/converters/keras/_topology2.py", line 714, in
build
self.make_output_layers()
File ".../venv/lib/python2.7/site-
packages/coremltools/converters/keras/_topology2.py", line 174, in
make_output_layers
self.model.output_layers]
IndexError: list index out of range
我怎样才能解决这个问题 ？