The network attribute <value> uses an Element Script evaluator configured with the Python language, which is only supported in ArcGIS Pro 3.6 or later and is not supported in ArcGIS Runtime.
Solution
This network dataset has an evaluator that is not supported by older versions of ArcGIS Pro or by ArcGIS Runtime. The package containing this network is not usable in those products. To create a package compatible with those products, change the network attribute's evaluators to a type supported by the client, or delete the network attribute entirely.