Important Notice - Forums is archived
To simplify things and help our users to be more productive, we have archived the current forum and focus our efforts on helping developers on Stack Overflow. You can post new questions on Stack Overflow or join our Discord channel.

Vaadin lets you build secure, UX-first PWAs entirely in Java.
Free ebook & tutorial.
ViSJS Addon Uncaught client side exception
Hi .
please advise what can be the cause for the attached screenshot of exception .
I'm using :
===== VERSION INFO ====
Client engine version 7.7.6Server engine version 7.7.6Theme version 7.7.6Push server version 2.2.9.vaadin2Push client version 2.2.13.vaadin5-javascript (note: does not need to match server version)Widget setAppWidgetsetTheme valoCommunication methodClient to server: XHR, server to client: -Heartbeat 300s
VISJS Addon Version 1.0.1.0 .
===== VERSION INFO ====
For widgetsets compilation I'm using gradle vaadin plugin .
The initial diagram is being painted at the loading time , but when switching off for another tab and awitching back , nothing is present in the screen .
Please tell me if I need to provide additional info .
thanks in advance