Question Client Error: Failed to spawn server object

Hey, I have both dragged the prefabs into the inspector and registered it in the networkmanager script but it still doesn't work. On the server everything works as expected.

Code (CSharp):

1. public class NetworkManager : Mirror.NetworkManager
2. {
3.     public override void OnStartClient()
4.     {
5.         var spawnablePrefabs = Resources.LoadAll<GameObject>("Assets/Prefabs/Spawnable");
6.         for (int i = 0; i < spawnablePrefabs.Length; i++)
7.             ClientScene.RegisterPrefab(spawnablePrefabs[i]);
8.     }
9.     public override void OnStartServer()
10.         => spawnPrefabs = Resources.LoadAll<GameObject>("Assets/Prefabs/Spawnable").ToList();
11. }

I get these two errors:

Spoiler: Error1

Failed to spawn server object, did you forget to add it to the NetworkManager? assetId=e34ffb03-4678-de04-9ab1-51775452d25a netId=3

Spoiler: Error2

Could not spawn assetId=e34ffb03-4678-de04-9ab1-51775452d25a scene=0 netId=3

Any suggestion on how to solve this issue?