The following test is failing in the JDK16 CI:

jdk/jfr/api/recording/event/TestReEnableName.java

Here's a snippet from the log file:

----------System.err:(16/1124)----------
java.lang.RuntimeException: Too few events found: expected 0 >= 5
at jdk.test.lib.Asserts.fail(Asserts.java:594)
at jdk.test.lib.Asserts.assertGreaterThanOrEqual(Asserts.java:288)
at jdk.jfr.api.recording.event.TestReEnableName.testRecordingWithEnabledEvent(TestReEnableName.java:93)
at jdk.jfr.api.recording.event.TestReEnableName.main(TestReEnableName.java:50)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:831)

JavaTest Message: Test threw exception: java.lang.RuntimeException: Too few events found: expected 0 >= 5
JavaTest Message: shutting down test

STATUS:Failed.`main' threw exception: java.lang.RuntimeException: Too few events found: expected 0 >= 5
----------rerun:(46/5440)*----------

This test has been failing with two failures on Win* in every
Tier5 CI job set since jdk-16+25-1595-tier5. That build-ID
contains the fix for the following:

    JDK-8255992 JFR EventWriter does not use first string from StringPool with id 0

so that's a good place to start investigating.