I have a client-server application, in which I use classic Sockets and threads for receiving/sending data and listening for clients.

The application works fine, but after some random time I get the ObjectDisposedException:

System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'MainForm'.
   at System.Windows.Forms.Control.MarshaledInvoke(Control caller, Delegate method, Object[] args, Boolean synchronous)
   at System.Windows.Forms.Control.Invoke(Delegate method, Object[] args)
   at System.Windows.Forms.Control.Invoke(Delegate method)

That code is called from client Socket thread and I use Invoke() method to run the code on UI thread.

I'm sure that I don't manually dispose the form nor using Close() (form is closed by user clicking Close button), so I don't know what could cause its disposing.