Client-Server Exception with VPN

Flow
1

Hi everyone,

we got a problem using one of our vaadin applications over vpn. From time to time we get internal errors, which lead to an unusable application until a refresh (F5) happened. The only thing i see is a logged exception, which seems to be occured in the internal client server communication.

java.lang.UnsupportedOperationException: Unexpected message id from the client. Expected sync id: 17, got 18. Message start: {“csrfToken”:“ecfa0463-e124-4c00-9ba4-d2f35168e9a4”,“rpc”:[{“type”:“event”,“node”:304,“event”:“click”,“data”:{“event.shiftKey”:false,“event.metaKey”:false,“event.detail”:1,“event.ctrlKey”:false,“event.clientX”:1498,“event.clientY”:354,“event.altKey”:false,“event.button”:0,“event.screenY”:457,“event.screenX”:1498}}]
,“syncId”:18,“clientId”:18}

Does anyone have an idea how we could avoid this error? If you need more information, i will try to provide it.

Thanks for your help!

Regards,
Sebastian

2

Expected sync id: 17, got 18 basically means that things have gone out-of-sync between the client and the server, most likely because some messages have been lost on the network. Recent versions of Vaadin have been updated to better cope with this situation. Please ensure you’re using Vaadin 14.1.19 or newer to have the latest fixes related to this problem.

3

Thanks for the anwser. I will give it a try with a newer version of vaadin (14.1.16 is used currently).

Regards, Sebastian