ValueError: Graph disconnected: cannot obtain value for tensor Tensor("input_16:0", shape=(None, 256, 256, 3), dtype=float32) at layer "l1". The following previous layers were accessed without issue: [] site:stackoverflow.com 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: []