IntelliJ cannot run tests since last update 2021.02

Solution for IntelliJ cannot run tests since last update 2021.02
is Given Below:

I have a very annoying problem.

I updated my IntelliJ lately to 2021.02

Since then I cannot run junit tests separately. If I run maven with tests, it works, build success with all tests. But if I want to execute test classes or methods separately (CTRL+SHIFT+F10), I got the following exception:

org.junit.runners.model.InvalidTestClassError: Invalid test class 'com.my.project.ServiceTestSpec':
  1. No runnable methods

    at org.junit.runners.ParentRunner.validate(ParentRunner.java:525)
    at org.junit.runners.ParentRunner.<init>(ParentRunner.java:102)
    at org.junit.runners.BlockJUnit4ClassRunner.<init>(BlockJUnit4ClassRunner.java:84)
    at org.junit.runners.JUnit4.<init>(JUnit4.java:23)
    at org.junit.internal.builders.JUnit4Builder.runnerForClass(JUnit4Builder.java:10)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:70)
    at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:37)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:70)
    at org.junit.internal.requests.ClassRequest.createRunner(ClassRequest.java:28)
    at org.junit.internal.requests.MemoizingRequest.getRunner(MemoizingRequest.java:19)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:50)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)

I deleted cache from IntelliJ, reloaded my application, rebuild maven, reload maven, reload everything.
And the very weird thing is that after reloading everything I can run a test class separately BUT ONLY FOR ONCE. For the next test run, I got again the error above. What the…

I use JDK 15.0.1

This is my current IntelliJ version:

enter image description here

This is a bug in IntelliJ IDEA, that will be fixed in 2021.2.1. See https://youtrack.jetbrains.com/issue/IDEA-274589

Here are the workarounds available:

  1. downgrade to the previous release, 2021.1.x (download distr from the site)

  2. run tests in a package

  3. run pattern configuration with the class you want to run (only class/method are affected)

  4. downgrade spock version (works fine for versions before 2.0)