'NoneType' object has no attribute '_inbound_nodes'

[uday2358]

input_shape_img = (None, None, 3)

img_input = Input(shape=input_shape_img) roi_input = Input(shape=(None, 4))

define the base network (VGG here, can be Resnet50, Inception, etc)

shared_layers = nn_base(img_input, trainable=True)

rpn = rpn_layer(shared_layers, num_anchors) classifier = classifier_layer(shared_layers, roi_input, C.num_rois, nb_classes=len(classes_count)) model_rpn = Model(img_input, rpn[:2]) model_classifier = Model(img_input,roi_input], classifier)

Error near model classifier........Can anyone help me solving this