UNetInvokeType moved to UNetwork.cs so that NetworkBehaviour is less cluttered and so that it can be used from other classes more easily.

Mirror/Runtime/NetworkBehaviour.cs

@@ -186,13 +186,6 @@ public virtual bool InvokeSyncEvent(int cmdHash, NetworkReader reader)
 
         public delegate void CmdDelegate(NetworkBehaviour obj, NetworkReader reader);
 
-        public enum UNetInvokeType
-        {
-            Command,
-            ClientRpc,
-            SyncEvent
-        }
-
         protected class Invoker
         {
             public UNetInvokeType invokeType;

Mirror/Runtime/UNetwork.cs

@@ -12,6 +12,14 @@ namespace Mirror
     // Handles requests to unspawn objects on the client
     public delegate void UnSpawnDelegate(GameObject spawned);
 
+    // invoke type for Cmd/Rpc/SyncEvents
+    public enum UNetInvokeType
+    {
+        Command,
+        ClientRpc,
+        SyncEvent
+    }
+
     // built-in system network messages
     // original HLAPI uses short, so let's keep short to not break packet header etc.
     // => use .ToString() to get the field name from the field value