I tired a lot to run the application as production. I added in application.properties "vaadin.productionMode=true" but so the error "Failed to load content of './frontend/index.html'. It is required to have './frontend/index.html' file when using..."
comes up. After I added in main/resources/META_INF/VAADIN/webapp the index.html with the content described in https://vaadin.com/docs/latest/fusion/application/starting#default-bootstrap-template-and-entry-point the error goes away the log files tells that the application has started in production ("Vaadin is running in production mode.") but unfortunately nothing is shown in the webbrowser.
Does anyone have an idea?
Thanks in advance, Thomas