'NoneType' has no len() concatenating 2 neural networks - deep-learning

Question

I'm coding a nn that has a img input and numeric, so img will be handled by cnn and numeric by dnn , then they concatenate and make calculations in a fully connected , here is code :
img_input = Input(shape = (99,4,4))
rr_input = Input(shape = (1))
price_input = Input(shape = (20))
legal_action_input = Input(shape = (9))
numeric_input = concatenate([rr_input,price_input, legal_action_input])
cnn = Conv2D(99, (4,4), activation='relu',padding='same', input_shape = (99,4,4))(img_input),
cnn = Dropout(0.2)(cnn)
cnn = Conv2D(99, (4,4), strides = (2,2), activation = 'relu', padding = 'same')(cnn)
cnn = Dropout(0.2)(cnn)
cnn = Conv2D(99, (4,4), strides = (2,2), activation = 'relu', padding = 'same')(cnn)
cnn = Dropout(0.2)(cnn)
cnn = Conv2D(99, (4,4), strides = (2,2), activation = 'relu', padding = 'same')(cnn)
cnn = MaxPooling3D(pool_size = (1,1,1),strides = 3)(cnn)
cnn = Dropout(0.2)(cnn)
cnn = Dense(64, activation = 'relu')(cnn)
cnn = Flatten()(cnn)
cnn = Model(inputs=img_input, outputs=cnn)
dnn = Dense(128, activation='relu', input_shape = (30,))(numeric_input)
dnn = Dropout(0.2)(dnn)
dnn = Dense(128, activation='relu')(dnn)
dnn = Dropout(0.2)(dnn)
dnn = Dense(64, activation='relu')(dnn)
#dnn = Flatten()(dnn)
dnn = Model(inputs=numeric_input, outputs=dnn)
merged = Concatenate()([cnn,dnn])
model = Dense(128, activation='relu')(merged)
model = Dropout(0.2)(model)
model = Dense(64, activation='relu')(model)
model = Dropout(0.2)(model)
model = Dense(9, activation='linear')(model)
model.compile(loss="mse", optimizer=Adam(args.lr))
but when I run them console prints :
--------------------------------------------------------------------------- TypeError Traceback (most recent call
last) Cell In[7], line 28
25 #dnn = Flatten()(dnn)
26 dnn = Model(inputs=numeric_input, outputs=dnn)
---> 28 merged = Concatenate()([cnn,dnn])
30 model = Dense(128, activation='relu')(merged)
31 model = Dropout(0.2)(model)
File
~/miniconda3/lib/python3.9/site-packages/keras/utils/traceback_utils.py:70,
in filter_traceback..error_handler(*args, **kwargs)
67 filtered_tb = _process_traceback_frames(e.traceback)
68 # To get the full stack trace, call:
69 # tf.debugging.disable_traceback_filtering()
---> 70 raise e.with_traceback(filtered_tb) from None
71 finally:
72 del filtered_tb
File
~/miniconda3/lib/python3.9/site-packages/keras/layers/merging/concatenate.py:97,
in Concatenate.build(self, input_shape)
94 #tf_utils.shape_type_conversion
95 def build(self, input_shape):
96 # Used purely for shape validation.
---> 97 if len(input_shape) < 1 or not isinstance(input_shape[0], tuple):
98 raise ValueError(
99 "A Concatenate layer should be called on a list of "
100 f"at least 1 input. Received: input_shape={input_shape}"
101 )
102 if all(shape is None for shape in input_shape):
TypeError: object of type 'NoneType' has no len()
where is the error ?