java.lang.ClassNotFoundException: org.junit.platform.engine.ConfigurationParameters Junit5 with eclipse

Question

I'm receiving the following exception:

java.lang.NoClassDefFoundError: org/junit/platform/engine/ConfigurationParameters
    at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.<init>(JUnit5TestLoader.java:34)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:64)
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
    at java.base/java.lang.reflect.ReflectAccess.newInstance(ReflectAccess.java:128)
    at java.base/jdk.internal.reflect.ReflectionFactory.newInstance(ReflectionFactory.java:350)
    at java.base/java.lang.Class.newInstance(Class.java:645)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.createRawTestLoader(RemoteTestRunner.java:371)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.createLoader(RemoteTestRunner.java:366)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.defaultInit(RemoteTestRunner.java:310)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.init(RemoteTestRunner.java:225)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
Caused by: java.lang.ClassNotFoundException: org.junit.platform.engine.ConfigurationParameters
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:606)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:168)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
    ... 13 more

Running JUnit 5 in an Eclipse project (no Maven). Does anyone know what causes this issue? Eclipse version: 2020-12 JUnit Version: 5

I was expecting JUnit 5 to run on Eclipse without further action.

Answer 1

The same error occured to me.

Solution: I had to add the JUnit library to the buildpath. Right click the class -> build path -> configure buildpath -> add libraries -> add JUnit

At this point one should add the new library not to the module path but to the entire class path.

JUnit tests are now running for me, though i had the same error as @AlBlue.