Invalid CSRF token on 7.4.3

Vaadin 6 / 7 / 8
1

FYI: It looks like ticket
17042
 was completed and released with 7.4.2. However, I’m running 7.4.3, and long repeating blocks of this message occasionally pop up in our production log output. It must timeout eventually, and doesn’t seem to prevent application useage. Though, I don’t know what the effects were, if any, on the user session(s) that caused it.

Vaadin 7.4.3
Java 7
vaadin4Spring spring-boot-vaadin 0.0.3
@push(default websocket/automatic)

WARN 21756 --- [o-8009-exec-184]
 c.v.server.communication.PushHandler     : Invalid CSRF token in new connection received from xx.xxx.x.xx1
WARN 21756 --- [o-8009-exec-238]
 c.v.server.communication.PushHandler     : Invalid CSRF token in new connection received from xx.xxx.x.xx2

I’m not sure how to manually force it to occur while working in dev, but I’ll be happy to try if someone can provide some pointers.

Thanks,
Sue