Unable to Start Network Manager (gameobjects) Host/Server even from Editor

I am unable to start Host/Server even from editor due to the following error:

NullReferenceException: Object reference not set to an instance of an object
Unity.Netcode.Components.NetworkTransform.InternalOnNetworkObjectParentChanged (Unity.Netcode.NetworkObject parentNetworkObject) (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Components/NetworkTransform.cs:3469)
Unity.Netcode.NetworkObject.InvokeBehaviourOnNetworkObjectParentChanged (Unity.Netcode.NetworkObject parentNetworkObject) (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Core/NetworkObject.cs:1820)
Unity.Netcode.NetworkObject.ApplyNetworkParenting (System.Boolean removeParent, System.Boolean ignoreNotSpawned, System.Boolean orphanedChildPass) (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Core/NetworkObject.cs:2238)
Unity.Netcode.NetworkSpawnManager.SpawnNetworkObjectLocallyCommon (Unity.Netcode.NetworkObject networkObject, System.UInt64 networkId, System.Boolean sceneObject, System.Boolean playerObject, System.UInt64 ownerClientId, System.Boolean destroyWithScene) (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Spawning/NetworkSpawnManager.cs:1113)
Unity.Netcode.NetworkSpawnManager.SpawnNetworkObjectLocally (Unity.Netcode.NetworkObject networkObject, System.UInt64 networkId, System.Boolean sceneObject, System.Boolean playerObject, System.UInt64 ownerClientId, System.Boolean destroyWithScene) (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Spawning/NetworkSpawnManager.cs:1021)
Unity.Netcode.NetworkSpawnManager.ServerSpawnSceneObjectsOnStartSweep () (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Spawning/NetworkSpawnManager.cs:1398)
Unity.Netcode.NetworkManager.HostServerInitialize () (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Core/NetworkManager.cs:1489)
Unity.Netcode.NetworkManager.StartHost () (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Core/NetworkManager.cs:1440)
UnityEngine.Debug:LogException(Exception)
Unity.Netcode.NetworkManager:StartHost() (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Core/NetworkManager.cs:1445)
Unity.Netcode.Editor.NetworkManagerEditor:DisplayCallToActionButtons() (at ./Library/PackageCache/com.unity.netcode.gameobjects/Editor/NetworkManagerEditor.cs:331)
Unity.Netcode.Editor.NetworkManagerEditor:OnInspectorGUI() (at ./Library/PackageCache/com.unity.netcode.gameobjects/Editor/NetworkManagerEditor.cs:395)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)

I have no idea what could cause it

Check any objects in the scene with a NetworkObject and NetworkTransform. One of them may not be setup correctly, eg a NetworkTransform without a NetworkObject.

If you aren’t on the lastest Netcode package, try upgrading.

Thanks for the reply! After a long dilemma I found out that the issue was the Network Object component on one of my singleton game objects! Now everything is working correctly!