Error in activation_model.predict(img_tensor)

[Caliber2]

activations = activation_model.predict(img_tensor)
File "/home/abc/.virtualenvs/myEmptyNewEnv/lib/python3.5/site-packages/keras/engine/training.py", line 1169, in predict
steps=steps)
File "/home/abc/.virtualenvs/myEmptyNewEnv/lib/python3.5/site-packages/keras/engine/training_arrays.py", line 294, in predict_loop
batch_outs = f(ins_batch)
File "/home/abc/.virtualenvs/myEmptyNewEnv/lib/python3.5/site-packages/keras/backend/tensorflow_backend.py", line 2715, in call
return self._call(inputs)
File "/home/abc/.virtualenvs/myEmptyNewEnv/lib/python3.5/site-packages/keras/backend/tensorflow_backend.py", line 2671, in _call
session)
File "/home/abc/.virtualenvs/myEmptyNewEnv/lib/python3.5/site-packages/keras/backend/tensorflow_backend.py", line 2623, in _make_callable
callable_fn = session._make_callable_from_options(callable_opts)
File "/home/abc/.virtualenvs/myEmptyNewEnv/lib/python3.5/site-packages/tensorflow/python/client/session.py", line 1471, in _make_callable_from_options
return BaseSession._Callable(self, callable_options)
File "/home/abc/.virtualenvs/myEmptyNewEnv/lib/python3.5/site-packages/tensorflow/python/client/session.py", line 1425, in init
session._session, options_ptr, status)
File "/home/abc/.virtualenvs/myEmptyNewEnv/lib/python3.5/site-packages/tensorflow/python/framework/errors_impl.py", line 528, in exit
c_api.TF_GetCode(self.status.status))
tensorflow.python.framework.errors_impl.InvalidArgumentError: input_1:0 is both fed and fetched.
Exception ignored in: <bound method BaseSession._Callable.del of <tensorflow.python.client.session.BaseSession._Callable object at 0x7f87b0106d30>>
Traceback (most recent call last):
File "/home/abc/.virtualenvs/myEmptyNewEnv/lib/python3.5/site-packages/tensorflow/python/client/session.py", line 1455, in del
self._session._session, self._handle, status)
File "/home/abc/.virtualenvs/myEmptyNewEnv/lib/python3.5/site-packages/tensorflow/python/framework/errors_impl.py", line 528, in exit
c_api.TF_GetCode(self.status.status))
tensorflow.python.framework.errors_impl.InvalidArgumentError: No such callable handle: 145176384

My steps:
model = build_model(....)
model.load_weights(..)
model.compile(...)
layer_outputs = [layer.output for layer in model.layers[:5]]
activation_model = models.Model(inputs=model.input, outputs=layer_outputs)
activations = activation_model.predict(img_tensor)#img_tensor is obtained as mentioned in ############################################################your steps except target_size is None

Please highlight where did I go wrong (I do get proper values in activation_model and img_tensor)