ValueError: Graph disconnected: cannot obtain value for tensor Tensor("input_4:0", shape=(None, 224, 224, 3), dtype=float32) at layer "block1_conv1". The following previous layers were accessed without issue: [] code example

Example: ValueError: Graph disconnected: cannot obtain value for tensor Tensor("input_3_1:0", shape=(None, None, 71), dtype=float32) at layer "input_3". The following previous layers were accessed without issue: []

ValueError: Graph disconnected: cannot obtain value for tensor Tensor("input_3_1:0", shape=(None, None, 71), dtype=float32) at layer "input_3". The following previous layers were accessed without issue: []