Internal Error - CompletionException

[Abdalion]

Hello, i am running a React Monaco frontend connected to the language server trough websocket. I randomly get this exception in my browsers console, otherwise it works correctly (even when i get the exception, autocomplete still works). If i reload the page with the monaco IDE, it sometimes shows the exception and sometimes doesnt.

Java Language Client:   Message: Internal error.
  Code: -32603 
java.util.concurrent.CompletionException: java.lang.ClassCastException: class org.eclipse.jdt.internal.core.JavaElementInfo cannot be cast to class org.eclipse.jdt.internal.core.ClassFileInfo (org.eclipse.jdt.internal.core.JavaElementInfo and org.eclipse.jdt.internal.core.ClassFileInfo are in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @636d4ab8)
	at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:315)
	at java.base/java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:320)
	at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:649)
	at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:483)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165)
Caused by: java.lang.ClassCastException: class org.eclipse.jdt.internal.core.JavaElementInfo cannot be cast to class org.eclipse.jdt.internal.core.ClassFileInfo (org.eclipse.jdt.internal.core.JavaElementInfo and org.eclipse.jdt.internal.core.ClassFileInfo are in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @636d4ab8)
	at org.eclipse.jdt.internal.core.ModularClassFile.getModule(ModularClassFile.java:301)
	at org.eclipse.jdt.internal.core.PackageFragmentRoot.getSourceModuleDescription(PackageFragmentRoot.java:928)
	at org.eclipse.jdt.internal.core.PackageFragmentRoot.getModuleDescription(PackageFragmentRoot.java:904)
	at org.eclipse.jdt.internal.core.JarPackageFragmentRoot.getModuleDescription(JarPackageFragmentRoot.java:307)
	at org.eclipse.jdt.internal.core.search.matching.JavaSearchNameEnvironment.addModuleClassPathInfo(JavaSearchNameEnvironment.java:301)
	at org.eclipse.jdt.internal.core.search.matching.JavaSearchNameEnvironment.mapToClassPathLocation(JavaSearchNameEnvironment.java:292)
	at org.eclipse.jdt.internal.core.search.matching.JavaSearchNameEnvironment.computeClasspathLocations(JavaSearchNameEnvironment.java:200)
	at org.eclipse.jdt.internal.core.search.matching.JavaSearchNameEnvironment.<init>(JavaSearchNameEnvironment.java:94)
	at org.eclipse.jdt.internal.core.search.matching.IndexBasedJavaSearchEnvironment.create(IndexBasedJavaSearchEnvironment.java:27)
	at org.eclipse.jdt.internal.core.search.matching.MatchLocator.initialize(MatchLocator.java:1239)
	at org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1277)
	at org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1390)
	at org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1532)
	at org.eclipse.jdt.internal.core.search.JavaSearchParticipant.locateMatches(JavaSearchParticipant.java:135)
	at org.eclipse.jdt.internal.core.search.BasicSearchEngine.findMatches(BasicSearchEngine.java:251)
	at org.eclipse.jdt.internal.core.search.BasicSearchEngine.search(BasicSearchEngine.java:602)
	at org.eclipse.jdt.core.search.SearchEngine.search(SearchEngine.java:670)
	at org.eclipse.jdt.ls.core.internal.handlers.CodeLensHandler.findReferences(CodeLensHandler.java:147)
	at org.eclipse.jdt.ls.core.internal.handlers.CodeLensHandler.resolve(CodeLensHandler.java:100)
	at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$18(JDTLanguageServer.java:691)
	at org.eclipse.jdt.ls.core.internal.BaseJDTLanguageServer.lambda$0(BaseJDTLanguageServer.java:75)
	at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:646)
	... 6 more