Cannot start JOSM due to a broken Plugin

[SlowMo24]

What steps will reproduce the problem?

1. Start JOSM

What is the expected result?

JOSM starts. If a broken plugin is encountered, it is deactivated

What happens instead?

JOSM hangs on "Loading Plugin PolygonCutOut" and shows the error interface.

Please provide any additional information below. Attach a screenshot if possible.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2023-01-03 21:28:24 +0100 (Tue, 03 Jan 2023)
Revision:18622
Build-Date:2023-01-04 02:30:56
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (18622 de) Linux Ubuntu 20.04.5 LTS
Memory Usage: 383 MB / 3996 MB (199 MB allocated, but free)
Java version: 11.0.17+8-post-Ubuntu-1ubuntu220.04, Ubuntu, OpenJDK 64-Bit Server VM
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Screen: :0.0 1920×1080 (scaling 1.00×1.00)
Maximum Screen Size: 1920×1080
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: ubuntu:GNOME
Java package: openjdk-11-jre:amd64-11.0.17+8-1ubuntu2~20.04
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:
+ Mapillary
+ PolygonCutOut
+ apache-commons (36034)
+ apache-http (35924)
+ buildings_tools
+ jna (36005)
+ undelete
+ wikipedia

Tagging presets:
+ https://josm.openstreetmap.de/josmfile?page=Presets/Healthcare&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Crafts&zip=1

Last errors/warnings:
- 00008.887 E: Handled by bug report queue: java.lang.UnsupportedClassVersionError: kiaatix/polygoncutout/PolygonCutOutPlugin has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 55.0
- 00008.965 W: Cannot lock cache directory. Will not use disk cache



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

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: main (1)
java.lang.UnsupportedClassVersionError: kiaatix/polygoncutout/PolygonCutOutPlugin has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 55.0
	at java.base/java.lang.ClassLoader.defineClass1(Native Method)
	at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
	at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:174)
	at java.base/java.net.URLClassLoader.defineClass(URLClassLoader.java:555)
	at java.base/java.net.URLClassLoader$1.run(URLClassLoader.java:458)
	at java.base/java.net.URLClassLoader$1.run(URLClassLoader.java:452)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:451)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:589)
	at org.openstreetmap.josm.plugins.PluginClassLoader.loadClass(PluginClassLoader.java:74)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
	at java.base/java.lang.Class.forName0(Native Method)
	at java.base/java.lang.Class.forName(Class.java:398)
	at org.openstreetmap.josm.plugins.PluginInformation.loadClass(PluginInformation.java:402)
	at org.openstreetmap.josm.plugins.PluginHandler.loadPlugin(PluginHandler.java:810)
	at org.openstreetmap.josm.plugins.PluginHandler.loadPlugins(PluginHandler.java:898)
	at org.openstreetmap.josm.plugins.PluginHandler.loadLatePlugins(PluginHandler.java:950)
	at org.openstreetmap.josm.gui.MainApplication.loadLatePlugins(MainApplication.java:1247)
	at org.openstreetmap.josm.gui.MainApplication.mainJOSM(MainApplication.java:962)
	at org.openstreetmap.josm.gui.MainApplication$3.processArguments(MainApplication.java:277)
	at org.openstreetmap.josm.gui.MainApplication.main(MainApplication.java:742)

[SlowMo24]

JOSM Startscreen where it hangs

[SlowMo24]

Because this won't let you open JSOM here is the workaround:

Open preferences.xml in .config/JOSM

comment out the plugin:

...
  <list key='plugins'>
    <!--<entry value='PolygonCutOut'/>-->
...

[SlowMo24]

I have also reported this to the maintainer of the plugin on ​https://github.com/bdxd111/JOSM-Polygon-Cut-Out/issues/5

[simon04]

Alternatively, start JOSM with --skip-plugins, see Help/CommandLineOptions#Programarguments

[skyper]

Fixed according to github.

[SlowMo24]

Yes, the plugin is fixed. But it would be a nice feature if JOSM could automatically handle this situation. In addition to launching the error dialog, the plugin could be disabled and the user could be notified. But thats of course a design choice I leave to you, I'm a happy JOSM user with or without ;-)