$ jabref --version
ERROR StatusLogger Log4j2 could not find a logging implementation. Please add log4j-core to the classpath. Using SimpleLogger to log to the console...
JabRef 5.0-beta.419--2020-02-12--3859620
Exception in Application stop method
ERROR FallbackExceptionHandler Uncaught exception occurred in Thread[main,5,main]
 java.lang.RuntimeException: Exception in Application stop method
	at org.jabref.merged.module/com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)
	at org.jabref.merged.module/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalAccessError: class kong.unirest.JsonObjectMapper (in module org.jabref.merged.module) cannot access class com.google.gson.Gson (in module com.google.gson) because module org.jabref.merged.module does not read module com.google.gson
	at org.jabref.merged.module/kong.unirest.JsonObjectMapper.<init>(Unknown Source)
	at org.jabref.merged.module/kong.unirest.Config.<init>(Unknown Source)
	at org.jabref.merged.module/kong.unirest.Unirest.<clinit>(Unknown Source)
	at org.jabref/org.jabref.Globals.stopBackgroundTasks(Unknown Source)
	at org.jabref/org.jabref.JabRefMain.stop(Unknown Source)
	at org.jabref.merged.module/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$10(Unknown Source)
	at org.jabref.merged.module/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(Unknown Source)
	at org.jabref.merged.module/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(Unknown Source)
	at java.base/java.security.AccessController.doPrivileged(Unknown Source)
	at org.jabref.merged.module/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(Unknown Source)
	at org.jabref.merged.module/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
	at org.jabref.merged.module/com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
	at org.jabref.merged.module/com.sun.glass.ui.gtk.GtkApplication.lambda$runLoop$11(Unknown Source)
	... 1 more
jabref --version  5,59s user 0,34s system 22% cpu 25,907 total