I am running different datasets with different numbers of clients on federated learning code. However, when working with some datasets, I can set the value of NUM_CLIENTS to a maximum of 20. When the client value exceeds 20, I encounter the error below. Where am I making a mistake?

I am experimenting with TensorFlow Federated and I would like to write a custom model aggregator for my training procedure, such that the distance of the client size from a certain predefined value is used to weight each client’s update (favouring some clients’ updates instead of others).