Fix all of the nullable issues

MistoxServer/Server/ServerConnection.cs

@@ -55,10 +55,11 @@ namespace Mistox.Server {
                         await ns.ReadExactlyAsync(payloadBuffer, 0, Header.DataLength, _cts.Token);
 
                         // Create the dataobject
-                        dynamic dataobject = DataPacket.Deserialize( Header, payloadBuffer.AsMemory(DataPacket.HeaderLength) );
-
-                        // Return the object
-                        _parent.InvokeDataReceived(this, dataobject);
+                        object? dataobject = DataPacket.Deserialize( Header, payloadBuffer.AsMemory(DataPacket.HeaderLength) );
+                        if (dataobject != null) {
+                            // Return the object
+                            _parent.InvokeDataReceived(this, dataobject);
+                        }
 
                     }
                 } catch (Exception e) {