Dear Jiaxiao Cau,
I could isolate the problem. It seems to be a bug caused by the display device. If you remove any call the wb_display_
* API in your controller, then it works in remote control. This is because a real e-puck has no display device.
We will fix this bug in the next version of Webots. Meanwhile I would recommend you as a work around to disable the wb_display_
* function in your e-puck controller programs.
Please let me know if that works for you.