All IDEA tests fail

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1

Files with *_ignored prefix appeared:

which have content like this:

// CONFIGURE_LIBRARY: JUnit@lib/junit-4.12.jar
// ERROR: Cannot access class 'java.lang.Class'. Check your module classpath for missing or conflicting dependencies
// ERROR: This annotation is not applicable to target 'member function'
import org.junit.Test

class A {
    @Test fun <caret>testTwoPlusTwoEqualsFour() {}
}

fun test() {
    A().testTwoPlusTwoEqualsFour()
}

Trying to run any test fails with the following error:

java.lang.NoClassDefFoundError: Could not initialize class org.jetbrains.kotlin.idea.test.KotlinWithJdkAndRuntimeLightProjectDescriptor

	at org.jetbrains.kotlin.AbstractImportsTest.getProjectDescriptor(AbstractImportsTest.kt:35)
	at com.intellij.testFramework.fixtures.LightCodeInsightFixtureTestCase.setUp(LightCodeInsightFixtureTestCase.java:109)
	at org.jetbrains.kotlin.idea.test.KotlinLightCodeInsightFixtureTestCase.setUp(KotlinLightCodeInsightFixtureTestCase.kt:56)
	at com.intellij.testFramework.UsefulTestCase.defaultRunBare(UsefulTestCase.java:352)
	at com.intellij.testFramework.EdtTestUtil$Companion$runInEdtAndWait$1.invoke(EdtTestUtil.kt:29)
	at com.intellij.testFramework.EdtTestUtil$Companion$runInEdtAndWait$1.invoke(EdtTestUtil.kt:27)
	at com.intellij.testFramework.EdtTestUtilKt$runInEdtAndWait$1.run(EdtTestUtil.kt:46)
	at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:303)
	at com.intellij.openapi.application.impl.LaterInvocator$1.run(LaterInvocator.java:165)
	at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.runNextEvent(LaterInvocator.java:410)
	at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.run(LaterInvocator.java:399)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.awt.EventQueue$3.run(EventQueue.java:703)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
	at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:827)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:655)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:365)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)