Java Model Exception: Java Model Status [src/main/java/suddenly.in.dot.notation [in some-maven-submodule] is not on its project's build path]

I have a maven project, with 5 submodules, nothing too special, Spring Boot 2, Lombok, AWS SDK. Project builds fine, ie, I can mvn test/compile/package/install to hearts' delight.

When I open this project in VS Code, I get the following errors (many of them, see also attached log):

!ENTRY org.eclipse.jdt.ls.core 4 0 2018-07-11 18:14:02.128
!MESSAGE Failed to publish diagnostics.
!STACK 1
Java Model Exception: Java Model Status [src/main/java/this.in.dot.notation.why [in aesop-dfp] is not on its project's build path]
	at org.eclipse.jdt.internal.core.JavaElement.newJavaModelException(JavaElement.java:580)
	at org.eclipse.jdt.internal.core.Openable.generateInfos(Openable.java:253)
	at org.eclipse.jdt.internal.core.Openable.openAncestors(Openable.java:527)
	at org.eclipse.jdt.internal.core.Openable.generateInfos(Openable.java:247)
	at org.eclipse.jdt.internal.core.Openable.openAncestors(Openable.java:527)
	at org.eclipse.jdt.internal.core.CompilationUnit.openAncestors(CompilationUnit.java:1240)
	at org.eclipse.jdt.internal.core.Openable.generateInfos(Openable.java:247)
	at org.eclipse.jdt.internal.core.JavaElement.openWhenClosed(JavaElement.java:593)
	at org.eclipse.jdt.internal.core.JavaElement.getElementInfo(JavaElement.java:323)
	at org.eclipse.jdt.internal.core.JavaElement.getElementInfo(JavaElement.java:309)
	at org.eclipse.jdt.internal.core.Openable.getBuffer(Openable.java:295)
	at org.eclipse.jdt.ls.core.internal.handlers.BuildWorkspaceHandler.publishDiagnostics(BuildWorkspaceHandler.java:112)
	at org.eclipse.jdt.ls.core.internal.handlers.BuildWorkspaceHandler.buildWorkspace(BuildWorkspaceHandler.java:65)
	at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$21(JDTLanguageServer.java:672)
	at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$22(JDTLanguageServer.java:716)
	at java.util.concurrent.CompletableFuture.uniApply(CompletableFuture.java:602)
	at java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:577)
	at java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:443)
	at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
	at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
	at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
	at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
!SUBENTRY 1 org.eclipse.jdt.core 4 1006 2018-07-11 18:14:02.132
!MESSAGE src/main/java/this.in.dot.notation.why [in aesop-dfp] is not on its project's build path

Note: I changed the package name.

Environment

• Operating System: Windows 10 x64
• JDK version: OpenJDK 8 r163 x64
• Visual Studio Code version: 1.25.0
• Java extension version: 0.28.0

Steps To Reproduce

1. Open Maven project in VS code
2. Open log file (see attached)

jdt-ls.log

Current Result

Code completion doesn't work.

Expected Result

Code completion works.

Comienza con el jdt-ls.log adjunto y sigue el stack trace a través de BuildWorkspaceHandler.publishDiagnostics/buildWorkspace y JDTLanguageServer. Reproduce la configuración del proyecto Maven con cinco submódulos descrita en el issue y, después, verifica que los diagnósticos del workspace ya no informen de que las fuentes Java están fuera del build path y que la finalización de código funcione.