Stream: General

Topic: Isabelle plugin load error

view this post on Zulip Jun Xu (Mar 09 2026 at 06:21):

Hi all,
My Isabelle/JEdit suddently got a plugin load error. The message looks like:
...\jedit\jars\isabelle_jedit_main.jar:
Cannot start:
*** [line 1 of "preferences"] error: bad input

*** ^
And when clicking the checkbox in plugin manager:
java.lang.NoClassDefFoundError: isabelle/jedit_main/Isabelle_Sidekick_Structure
at java.base/java.lang.ClassLoader.defineClass1(Native Method)
at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1027)
at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:889)
at org.gjt.sp.jedit.JARClassLoader._loadClass(JARClassLoader.java:435)
at org.gjt.sp.jedit.JARClassLoader.loadClass(JARClassLoader.java:112)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526)
at org.gjt.sp.jedit.bsh.classpath.ClassManagerImpl.classForName(ClassManagerImpl.java:204)
at org.gjt.sp.jedit.bsh.NameSpace.classForName(NameSpace.java:1320)
at org.gjt.sp.jedit.bsh.NameSpace.getClassImpl(NameSpace.java:1220)
at org.gjt.sp.jedit.bsh.NameSpace.getClass(NameSpace.java:1161)
at org.gjt.sp.jedit.bsh.Name.consumeNextObjectField(Name.java:298)
at org.gjt.sp.jedit.bsh.Name.toObject(Name.java:199)
at org.gjt.sp.jedit.bsh.BSHAmbiguousName.toObject(BSHAmbiguousName.java:60)
at org.gjt.sp.jedit.bsh.BSHAllocationExpression.objectAllocation(BSHAllocationExpression.java:86)
at org.gjt.sp.jedit.bsh.BSHAllocationExpression.eval(BSHAllocationExpression.java:62)
at org.gjt.sp.jedit.bsh.BSHPrimaryExpression.eval(BSHPrimaryExpression.java:102)
at org.gjt.sp.jedit.bsh.BSHPrimaryExpression.eval(BSHPrimaryExpression.java:47)
at org.gjt.sp.jedit.bsh.Interpreter.eval(Interpreter.java:644)
at org.gjt.sp.jedit.bsh.Interpreter.eval(Interpreter.java:738)
at org.gjt.sp.jedit.bsh.Interpreter.eval(Interpreter.java:727)
at org.gjt.sp.jedit.BeanShellFacade._eval(BeanShellFacade.java:153)
at org.gjt.sp.jedit.BeanShellFacade.eval(BeanShellFacade.java:117)
at org.gjt.sp.jedit.BeanShell.eval(BeanShell.java:382)
at org.gjt.sp.jedit.ServiceManager$Descriptor.getInstance(ServiceManager.java:337)
at org.gjt.sp.jedit.ServiceManager.getService(ServiceManager.java:262)
at sidekick.SideKickPlugin.getParser(SideKickPlugin.java:237)
at sidekick.SideKickPlugin.getParserForBuffer(SideKickPlugin.java:293)
at sidekick.SideKick.setParser(SideKick.java:214)
at sidekick.SideKick.handlePluginUpdate(SideKick.java:345)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at org.gjt.sp.jedit.EditBus.dispatch(EditBus.java:242)
at org.gjt.sp.jedit.EditBus.sendImpl(EditBus.java:281)
at org.gjt.sp.jedit.EditBus$SendMessage.run(EditBus.java:442)
at org.gjt.sp.jedit.EditBus.send(EditBus.java:206)
at org.gjt.sp.jedit.jEdit.addPluginJAR(jEdit.java:1251)
at org.gjt.sp.jedit.PluginJAR.load(PluginJAR.java:207)
at org.gjt.sp.jedit.pluginmgr.ManagePanel$PluginTableModel$1.run(ManagePanel.java:563)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
Caused by: java.lang.ClassNotFoundException: isabelle.jedit_main.Isabelle_Sidekick_Structure
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526)
at org.gjt.sp.jedit.JARClassLoader.loadFromParent(JARClassLoader.java:518)
at org.gjt.sp.jedit.JARClassLoader.loadClass(JARClassLoader.java:90)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526)
... 51 more
I am on Windows, and the error occurred today for no reason. Do you know what it is ?

view this post on Zulip Jun Xu (Mar 09 2026 at 06:36):

Hi all,
So after downloading Isabelle 2025-02 things work again. It seems like the old version is phased out.

view this post on Zulip Manuel Eberl (Mar 17 2026 at 10:06):

I don't think the old version should be "phased out" in any sense. I have no idea what this could be, but I think I had a similar problem with isabelle-dev a week ago or so. I eventually solved it by just deleting the .isabelle folder and reinstalling it.

Last updated: Mar 20 2026 at 05:16 UTC