Does UIDetachedException means shakeHands fail?

Vaadin 6 / 7 / 8
1

I open the Chrome browser code and find there are several error send path is url:.../heartbeat/uid=3? that fail to response.
And my application console print UIDetachedException.

  1. How this problem happen?
  2. How can I avoid this Exception within my code?
  3. Is there a shakehands between browser and Vaadin?

I’m using Vaadin 8.