java.lang.NoClassDefFoundError: Could not initialize class org.openstreetmap.josm.actions.SessionSaveAction

[anonymous]

I have started JOSM normally. For a very long time only the small startup window appeared, until at some point the error message appeared.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2022-07-07 23:02:39 +0200 (Thu, 07 Jul 2022)
Revision:18513
Build-Date:2022-07-08 01:30:57
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (18513 de) Linux Ubuntu 20.04.4 LTS
Memory Usage: 114 MB / 1970 MB (74 MB allocated, but free)
Java version: 14.0.2+12-Ubuntu-120.04, Private Build, OpenJDK 64-Bit Server VM
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Screen: :0.0 1366×768 (scaling 1.00×1.00)
Maximum Screen Size: 1366×768
Best cursor sizes: 16×16→16×16, 32×32→32×32
Environment variable LANG: de_DE.UTF-8
System property file.encoding: UTF-8
System property sun.jnu.encoding: UTF-8
Locale info: de_DE
Numbers with default locale: 1234567890 -> 1234567890
Desktop environment: KDE
Java ATK Wrapper package: libatk-wrapper-java:all-0.37.1-1
libcommons-logging-java: libcommons-logging-java:all-1.2-2
fonts-noto: fonts-noto:all-20200323-1build1~ubuntu20.04.1
VM arguments: [--module-path=/usr/share/openjfx/lib, --add-modules=java.scripting,java.sql,javafx.controls,javafx.media,javafx.swing,javafx.web, -Djosm.restart=true, -Djava.net.useSystemProxies=true, --add-exports=java.base/sun.security.action=ALL-UNNAMED, --add-exports=java.desktop/com.sun.imageio.plugins.jpeg=ALL-UNNAMED, --add-exports=java.desktop/com.sun.imageio.spi=ALL-UNNAMED]

Plugins:
+ DirectUpload
+ Mapillary
+ apache-commons
+ apache-http
+ editgpx
+ jna

Last errors/warnings:
- 00002.317 E: Exception raised in EDT: java.util.concurrent.ExecutionException: java.lang.ExceptionInInitializerError. Ursache: java.lang.ExceptionInInitializerError. Ursache: java.lang.NullPointerException
- 00002.328 E: Exception raised in EDT: java.util.concurrent.ExecutionException: java.lang.NoClassDefFoundError: Could not initialize class org.openstreetmap.josm.actions.SessionSaveAction. Ursache: java.lang.NoClassDefFoundError: Could not initialize class org.openstreetmap.josm.actions.SessionSaveAction
- 00006.951 E: Handled by bug report queue: java.lang.NoClassDefFoundError: Could not initialize class org.openstreetmap.josm.actions.SessionSaveAction



=== REPORTED CRASH DATA ===
BugReportExceptionHandler#handleException:
No data collected.

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: main (1)
java.lang.NoClassDefFoundError: Could not initialize class org.openstreetmap.josm.actions.SessionSaveAction
	at org.openstreetmap.josm.gui.MainMenu.<init>(MainMenu.java:181)
	at org.openstreetmap.josm.gui.MainFrame.initialize(MainFrame.java:93)
	at org.openstreetmap.josm.gui.MainApplication.initializeMainWindow(MainApplication.java:415)
	at org.openstreetmap.josm.spi.lifecycle.InitializationTask.call(InitializationTask.java:33)
	at org.openstreetmap.josm.spi.lifecycle.Lifecycle.runInitializationTasks(Lifecycle.java:103)
	at org.openstreetmap.josm.spi.lifecycle.Lifecycle.initialize(Lifecycle.java:71)
	at org.openstreetmap.josm.gui.MainApplication.mainJOSM(MainApplication.java:953)
	at org.openstreetmap.josm.gui.MainApplication$3.processArguments(MainApplication.java:277)
	at org.openstreetmap.josm.gui.MainApplication.main(MainApplication.java:741)

[anonymous]

Update: Reinstalling JOSM via

$ sudo apt purge josm
$ sudo apt install josm

solved the problem.

[taylor.smock]

I don't know why this is happening. This is the third or fourth instance I've seen.