【Java】monitor.exe 起動時に「An error has occurred. See the log file XXXX」

はじめに

An error has occurred. See the log file XXXX

monitor.exe 起動時に上記のエラーが発生して起動できない現象に遭遇した
ログファイルには以下のように出力されていた

!SESSION XXXX -----------------------------------------------
eclipse.buildId=unknown
java.version=17.0.2
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=ja_JP
Command-line arguments:  -os win32 -ws win32 -arch x86_64 -data @noDefault

!ENTRY org.eclipse.osgi 4 0 XXXX
!MESSAGE error loading hook: org.eclipse.osgi.internal.baseadaptor.BaseHookConfigurator
!STACK 0
java.lang.reflect.InaccessibleObjectException: Unable to make protected void java.net.URLClassLoader.addURL(java.net.URL) accessible: module java.base does not "opens java.net" to unnamed module @7a5d012c
    at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:354)
    at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
    at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:199)
    at java.base/java.lang.reflect.Method.setAccessible(Method.java:193)
    at org.eclipse.osgi.internal.baseadaptor.BaseStorage.findMethod(BaseStorage.java:174)
    at org.eclipse.osgi.internal.baseadaptor.BaseStorage.findMethod(BaseStorage.java:181)
    at org.eclipse.osgi.internal.baseadaptor.BaseStorage.findAddURLMethod(BaseStorage.java:165)
    at org.eclipse.osgi.internal.baseadaptor.BaseStorage.<init>(BaseStorage.java:135)
    at org.eclipse.osgi.internal.baseadaptor.BaseHookConfigurator.addHooks(BaseHookConfigurator.java:24)
    at org.eclipse.osgi.baseadaptor.HookRegistry.loadConfigurators(HookRegistry.java:178)
    at org.eclipse.osgi.baseadaptor.HookRegistry.initialize(HookRegistry.java:100)
    at org.eclipse.osgi.baseadaptor.BaseAdaptor.<init>(BaseAdaptor.java:98)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77)
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499)
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.createAdaptor(EclipseStarter.java:737)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.startup(EclipseStarter.java:258)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:568)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1438)

!ENTRY org.eclipse.osgi 4 0 XXXX
!MESSAGE Startup error
!STACK 1
java.lang.NullPointerException: Cannot invoke "org.eclipse.osgi.internal.baseadaptor.BaseStorage.initialize(org.eclipse.osgi.baseadaptor.BaseAdaptor)" because "this.storage" is null
    at org.eclipse.osgi.baseadaptor.BaseAdaptor.initializeStorage(BaseAdaptor.java:123)
    at org.eclipse.osgi.framework.internal.core.Framework.<init>(Framework.java:192)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.startup(EclipseStarter.java:262)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:568)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1438)

解決方法

環境変数に「JAVA_HOME」を追加して PC を再起動したら
正常に起動できるようになった

参考サイト様