Invalid service: net.imagej.legacy.LegacyService

[MurphyHou123]

It can't run with error for all demos: Exception in thread "main" java.lang.IllegalArgumentException: Invalid service: net.imagej.legacy.LegacyService at org.scijava.service.ServiceHelper.createExactService(ServiceHelper.java:278) at org.scijava.service.ServiceHelper.loadService(ServiceHelper.java:229) at org.scijava.service.ServiceHelper.loadService(ServiceHelper.java:192) at org.scijava.service.ServiceHelper.loadServices(ServiceHelper.java:164) at org.scijava.Context.(Context.java:285) at org.scijava.Context.(Context.java:234) at org.scijava.Context.(Context.java:174) at org.scijava.Context.(Context.java:160) at net.imagej.ImageJ.(ImageJ.java:75) at SwingExample.main(SwingExample.java:20) Caused by: java.lang.ExceptionInInitializerError at java.base/jdk.internal.misc.Unsafe.ensureClassInitialized0(Native Method) at java.base/jdk.internal.misc.Unsafe.ensureClassInitialized(Unsafe.java:1160) at java.base/jdk.internal.reflect.MethodHandleAccessorFactory.ensureClassInitialized(MethodHandleAccessorFactory.java:300) at java.base/jdk.internal.reflect.MethodHandleAccessorFactory.newConstructorAccessor(MethodHandleAccessorFactory.java:103) at java.base/jdk.internal.reflect.ReflectionFactory.newConstructorAccessor(ReflectionFactory.java:200) at java.base/java.lang.reflect.Constructor.acquireConstructorAccessor(Constructor.java:547) at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:497) at java.base/java.lang.reflect.ReflectAccess.newInstance(ReflectAccess.java:128) at java.base/jdk.internal.reflect.ReflectionFactory.newInstance(ReflectionFactory.java:304) at java.base/java.lang.Class.newInstance(Class.java:685) at org.scijava.service.ServiceHelper.createServiceRecursively(ServiceHelper.java:300) at org.scijava.service.ServiceHelper.createExactService(ServiceHelper.java:267) ... 9 more Caused by: java.lang.RuntimeException: No _hooks field found in ij.IJ It appears that this class was already defined in the class loader! Please make sure that you initialize the LegacyService before using any ImageJ 1.x class. You can do that by adding this static initializer:

static {
	LegacyInjector.preinit();
}

I tried to add LegacyInjector.preinit(); but still failed.

[sean-leichtle]

@MurphyHou123 Have you tried a 1.8 JDK?

[ctrueden]

@MurphyHou123 I second what @sean-leichtle suggests, to use OpenJDK 8. The new module system in Java 9 was tightened up in Java 17+ to make imagej-legacy's job of patching the original ImageJ more difficult.

Alternately, if you really need to use Java 17+, you can try launching with --add-opens=java.base/java.lang=ALL-UNNAMED passed to the JVM.