ADDITIONAL SYSTEM INFORMATION :
Reproduced on Mac OS Catalina 10.15.3 with JRE 1.8.0_251-b08


A DESCRIPTION OF THE PROBLEM :
Anytime nearly an accessibility or "Universal Access" application is used on Mac, users of MATLAB will experience the following Java stack trace after a few minutes of use. What triggers it does not seem to be consistent, but it does frequently enough that it is expected in ever session of use.

java.lang.NullPointerException
at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:54)
at sun.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36)
at java.lang.reflect.Field.get(Field.java:379)
at sun.lwawt.macosx.CAccessibility.getAccessibleRoleFor(CAccessibility.java:220)
at sun.lwawt.macosx.CAccessibility$11.call(CAccessibility.java:235)
at sun.lwawt.macosx.CAccessibility$11.call(CAccessibility.java:232)
at sun.lwawt.macosx.LWCToolkit$CallableWrapper.run(LWCToolkit.java:521)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:302)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:738)
at java.awt.EventQueue.access$300(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:699)
at java.awt.EventQueue$3.run(EventQueue.java:697)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:713)
at java.awt.EventQueue$4.run(EventQueue.java:711)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:710)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Reproduces in all versions of MATLAB after at least R2017b.
Requires installing nearly any accessibility application on Mac OS X.
Some well known applications that trigger this issue include PopClip, Moom, and BetterSnapTool.




CUSTOMER SUBMITTED WORKAROUND :
The only known workaround has been to remove these accessibility applications.

FREQUENCY : always