Jmeter 5.4 - java.lang.NullPointerException in thread Thread[AWT-EventQueue-0,6,main]

Question

Trying to use the latest Jmeter version 5.4, however when imported the recorded script using Blazemeter to Jmeter and tried to disable/perform any action on Jmeter UI, getting the below error.

Uncaught Exception java.lang.NullPointerException in thread Thread[AWT-EventQueue-0,6,main]. See log file for details.

I have Java 8, earlier Jmeter versions worked fine. Facing this issue with the latest version only.

jmeter.log file:

 2021-01-21 17:34:33,542 ERROR o.a.j.JMeter: Uncaught exception in thread Thread[AWT-EventQueue-0,6,main]
java.lang.NullPointerException: null
    at com.github.weisj.darklaf.ui.cell.hint.CellHintPopupListener.lambda$enter$0(CellHintPopupListener.java:234) ~[darklaf-core-2.4.10.jar:2.4.10]
    at java.awt.event.InvocationEvent.dispatch(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventQueue.access$500(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventQueue$3.run(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventQueue$3.run(Unknown Source) ~[?:1.8.0_231]
    at java.security.AccessController.doPrivileged(Native Method) ~[?:1.8.0_231]
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventQueue.dispatchEvent(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) [?:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) [?:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) [?:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source) [?:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source) [?:1.8.0_231]
    at java.awt.EventDispatchThread.run(Unknown Source) [?:1.8.0_231]
2021-01-21 17:34:50,507 ERROR o.a.j.JMeter: Uncaught exception in thread Thread[AWT-EventQueue-0,6,main]
java.lang.NullPointerException: null
    at com.github.weisj.darklaf.ui.cell.hint.CellHintPopupListener.lambda$enter$0(CellHintPopupListener.java:234) ~[darklaf-core-2.4.10.jar:2.4.10]
    at java.awt.event.InvocationEvent.dispatch(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventQueue.access$500(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventQueue$3.run(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventQueue$3.run(Unknown Source) ~[?:1.8.0_231]
    at java.security.AccessController.doPrivileged(Native Method) ~[?:1.8.0_231]
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventQueue.dispatchEvent(Unknown Source) ~[?:1.8.0_231]
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) [?:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) [?:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) [?:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source) [?:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source) [?:1.8.0_231]
    at java.awt.EventDispatchThread.run(Unknown Source) [?:1.8.0_231]

Answer 1

It looks like you're experiencing JMeter Bug 64957 there are following options:

1. Downgrade to JMeter 5.3 , it can be downloaded from JMeter archives folder
2. Upgrade to a nightly build , it can be downloaded from Jenkins