Live Reload in Vaadin 14.3 - error

I have try Live Reload option in V14.3, but I get error for standard Vaadin Start up app. Use case :

  • create Spring boot app via
  • open project in IDEA and run as Spring Boot app.
  • test app in Chrome browser - it works.
  • change “Say hello” to “Say hello 1”
  • reload class in IDEA (Ctrl + Shift + F9)
  • now page is automatically reload and it get the attach image error.


Hi Matic. For my sample project is working great. Are you using DCEVM or something similar?

No, i don’t thing so. Because project is standard Vaadin start project. I also try the following combination :

  • JDK 1.8 + start app as IDEA Sprint boot app
  • JDK 1.8 + start app as IDEA Maven app
  • JDK 14.1 + start app as IDEA Sprint boot app
    All with some result - error page as describe in original post.

I tried exactly the same project as you now and it’s working as expected.
And I am using

It’s nice to see somebody else using Vaadin in Slovenia :slight_smile:

This is not related to Live Reload functionality.
This happens without any Live Reload (Vaadin functionality).
It happens because of Spring Boot dev tools.
We have a ticket for this :
and I believe there is another duplicate.

Test result :

  • After installing TravaOpenJDK it starts working,
  • it is a nice experience for small changes (label, width change, etc.). But if I add a new method, I get “java.lang.reflect.GenericSignatureFormatError: Signature Parse error: Expected Field Type Signature”
  • as far as I can see, TravaOpenJDK is using JDK 11. All our Vaadin apps are using JDK14 with new features. So unfortunately, for now, we cannot use this for development

Thank you for all the help!