UI gets disabled (grayed out)

Hi Guy,
our customers are complaining about a problem that sporadically UI gets disabled while working. (my assumption is that the client lost the connection to server). There is no error on the server logs. client doesn’t show any error as well.

Its just that the application stop working and grayed out. see the example as attached file.

any ideas whats going on here. since i can’t reproduce the error but the client ist getting it regularly.

Thanks for any help in this regard,


Following Error is to be seen in Chorme Console:

vaadinPush.js?v=7.7.12:1 Websocket closed, reason: Normal closure; the connection successfully completed whatever purpose for which it was created. - wasClean: true

log @ vaadinPush.js?v=7.7.12:1

2:8025/AdSuite5/HEARTBEAT/?v-uiId=0 Failed to load resource: the server responded with a status of 404 (Introuvable)