KeyError: "The name 'image_tensor:0' refers to a Tensor which does not exist. The operation, 'image_tensor', does not exist in the graph."

[ZIKO94ZIKO]

i have this error ;

Traceback (most recent call last): File "VehicleMoniter.py", line 278, in <module> image_tensor = tf.get_default_graph().get_tensor_by_name('image_tensor:0') File "C:\Users\Zakaria\Anaconda3\lib\site-packages\tensorflow\python\framework\ops.py", line 3972, in get_tensor_by_name return self.as_graph_element(name, allow_tensor=True, allow_operation=False) File "C:\Users\Zakaria\Anaconda3\lib\site-packages\tensorflow\python\framework\ops.py", line 3796, in as_graph_element return self._as_graph_element_locked(obj, allow_tensor, allow_operation) File "C:\Users\Zakaria\Anaconda3\lib\site-packages\tensorflow\python\framework\ops.py", line 3838, in _as_graph_element_locked "graph." % (repr(name), repr(op_name))) KeyError: "The name 'image_tensor:0' refers to a Tensor which does not exist. The operation, 'image_tensor', does not exist in the graph."