Why do I recieve java.lang.​NullPointe​rException and lots of other errors when I run my PEM-FC?

Im extremely new to matlab and simulink and this may be obvious but how could I fix this? The list Goes as:

java.lang.NullPointerException

at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:57)

at sun.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36)

at java.lang.reflect.Field.get(Field.java:393)

at sun.lwawt.macosx.CAccessibility.getAccessibleRoleFor(CAccessibility.java:248)

at sun.lwawt.macosx.CAccessibility$12.call(CAccessibility.java:263)

at sun.lwawt.macosx.CAccessibility$12.call(CAccessibility.java:260)

at sun.lwawt.macosx.LWCToolkit$CallableWrapper.run(LWCToolkit.java:597)

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

at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)

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:74)

at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:84)

at java.awt.EventQueue$4.run(EventQueue.java:733)

at java.awt.EventQueue$4.run(EventQueue.java:731)

at java.security.AccessController.doPrivileged(Native Method)

at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)

at java.awt.EventQueue.dispatchEvent(EventQueue.java:730)

at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)

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)

I really do not know what this means

Answer 1

[Shlok]

Hi Mason,

"java.lang.NullPointerException" error is often caused by third-party accessibility tools on Mac interfering with MATLAB. You can try fixing it by opening System Preferences > Security & Privacy > Privacy tab, selecting Accessibility, and disabling any third-party tools listed there.

Additionally, for future reference, you might find it helpful to look up the stack trace on MATLAB Answers, as similar issues have been discussed there. For example:

• https://www.mathworks.com/matlabcentral/answers/350953-why-do-i-receive-a-java-exception-when-i-open-the-profiler-on-mac
• https://www.mathworks.com/matlabcentral/answers/400717-why-do-i-get-a-java-exception-when-i-close-a-simulink-project