Cannot access a disposed object.

[azzahrah]

Cannot access a disposed object.

[juhgiyo]

Any more detail on the error?

[azzahrah]

This error fire when i try disconnect clients, then i try stop server....

[juhgiyo]

As it is handled by try-catch clause, you can just ignore the error.
The message is there just to inform that such exception is occurred.
The error is simple, you disconnected the client which is in the middle of connection to the server.
And when you stopped the server, the server stops the listening socket, and tries to clean up the client that is in connection.
As this client is already disconnected, it is already cleaned up, but the server tries to clean up as the listening socket is closed, which results accessing disposed object.

Simple word, you can ignore the error without any concern.