What's mean of the error message about macos java?

After startup, the following message appears in the command window.

Is it a bug?

My machine is Mac mini Late 2018, macOS Mojave 10.14.1, and the version of MATLAB is R2018b (9.5.0.944444).

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java.lang.reflect.InvocationTargetException

at sun.lwawt.macosx.LWCToolkit.invokeAndWait(LWCToolkit.java:649)

at sun.lwawt.macosx.CInputMethod.selectedRange(CInputMethod.java:638)

Caused by: java.lang.NullPointerException

at sun.lwawt.macosx.CInputMethod$4.run(CInputMethod.java:640)

at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:301)

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 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)

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