This test used to fail with b160 but not with b161 (see JDK-8176560) reporting incorrect operation of setLocationRelativeTo(). Now, it fails again, always, on my dual screen OEL 7.1 system, this time with
java.lang.IllegalArgumentException: Window must not be zero

The failure is reproducible with b167 and a PIT build for b169. Unfortunately, the test cannot compile as is with b162 after the latest module-related changes. Please ensure this issue is not related to them and adjust the priority if necessary.
Note, however, that on my other dual screen system with Ubuntu 16.04 (Unity) the issue is NOT reproducible.

Here's the stack trace:

java.lang.IllegalArgumentException: Window must not be zero
at java.desktop/sun.awt.X11.XAtom.checkWindow(XAtom.java:774)
at java.desktop/sun.awt.X11.XAtom.getAtomData(XAtom.java:465)
at java.desktop/sun.awt.X11.XToolkit.getWorkArea(XToolkit.java:711)
at java.desktop/sun.awt.X11.XToolkit.getInsets(XToolkit.java:787)
at java.desktop/sun.awt.X11.XToolkit.getScreenInsets(XToolkit.java:775)
at java.desktop/java.awt.Window.init(Window.java:504)
at java.desktop/java.awt.Window.<init>(Window.java:434)
at java.desktop/java.awt.Frame.<init>(Frame.java:449)
at LocationRelativeToTest.main(LocationRelativeToTest.java:74)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:563)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
at java.base/java.lang.Thread.run(Thread.java:844)