Deployment on Liberty 18 fails with NPE

[Artur-]

Exception = java.lang.NullPointerException
Source = com.ibm.ws.webcontainer.osgi.DynamicVirtualHost
probeid = startWebApp
Stack Dump = java.lang.NullPointerException
at com.vaadin.flow.server.startup.RouteRegistry.setErrorNavigationTargets(RouteRegistry.java:229)
at com.vaadin.flow.server.startup.ErrorNavigationTargetInitializer.onStartup(ErrorNavigationTargetInitializer.java:50)
at com.ibm.ws.webcontainer.webapp.WebApp.initializeServletContainerInitializers(WebApp.java:2487)
at com.ibm.ws.webcontainer.webapp.WebApp.initialize(WebApp.java:994)
at com.ibm.ws.webcontainer.webapp.WebApp.initialize(WebApp.java:6566)
at com.ibm.ws.webcontainer.osgi.DynamicVirtualHost.startWebApp(DynamicVirtualHost.java:467)
at com.ibm.ws.webcontainer.osgi.DynamicVirtualHost.startWebApplication(DynamicVirtualHost.java:462)
at com.ibm.ws.webcontainer.osgi.WebContainer.startWebApplication(WebContainer.java:1132)
at com.ibm.ws.webcontainer.osgi.WebContainer.access$000(WebContainer.java:108)
at com.ibm.ws.webcontainer.osgi.WebContainer$3.run(WebContainer.java:944)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

Can be seen by deploying Beverage Buddy. Extracted from #3960 which is about production build problems. This fails also in development mode.

[Legioth]

It's been 9 months, so I guess nobody remembers why this issue is assigned to the 1.0.4 milestone even though the original fix is only included starting from the 1.1 branch and has seemingly not been backported to the 1.0 branch?