Error: Communication to camera admin failed.

[lygoon]

Hello, I am trying to do experiments by using a joy to control an Axis camera.
When I run "./FIRST_CameraControl", some information appeared as below:
Found 1 cameras in config file.
Found 1 joysticks.
Conecting to 1 cameras.
Assigning joystick 0 to camera admin(192.168.104.88).
Connecting to camera admin (192.168.104.88)...
Connected to camera admin!
Then, I pushed the joystick. However, an error occurred as below:
Error: Communication to camera admin failed.
You have likely lost connection. This camera will now be disabled.

So, how can I solve it? Could you please help me? Thanks!