Cant run Jmeter on Ubuntu - No X11 DISPLAY variable was set

I get error when i run Jmeter that -

An error occurred: 
No X11 DISPLAY variable was set,
or no headful library support was found,
but this program performed an operation which requires it,

But my variable is SET. display variable

2022-12-02 14:38:39,871 INFO o.a.j.u.JMeterUtils: Setting Locale to en_EN
2022-12-02 14:38:39,885 INFO o.a.j.JMeter: Loading user properties from: user.properties
2022-12-02 14:38:39,885 INFO o.a.j.JMeter: Loading system properties from: system.properties
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: Copyright (c) 1998-2022 The Apache Software Foundation
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: Version 5.5
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: java.version=19.0.1
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: java.vm.name=OpenJDK 64-Bit Server VM
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: os.name=Linux
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: os.arch=amd64
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: os.version=5.15.0-56-generic
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: file.encoding=UTF-8
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: java.awt.headless=null
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: Max memory     =1073741824
2022-12-02 14:38:39,890 INFO o.a.j.JMeter: Available Processors =8
2022-12-02 14:38:39,897 INFO o.a.j.JMeter: Default Locale=English (EN)
2022-12-02 14:38:39,897 INFO o.a.j.JMeter: JMeter  Locale=English (EN)
2022-12-02 14:38:39,897 INFO o.a.j.JMeter: JMeterHome=/home/ankur/software/jmeter/apache-jmeter-5.5
2022-12-02 14:38:39,897 INFO o.a.j.JMeter: user.dir  =/home/ankur/software/jmeter/apache-jmeter-5.5/bin
2022-12-02 14:38:39,898 INFO o.a.j.JMeter: PWD       =/home/ankur/software/jmeter/apache-jmeter-5.5/bin
2022-12-02 14:38:39,898 INFO o.a.j.JMeter: IP: 127.0.1.1 Name: ankur FullName: ankur
2022-12-02 14:38:39,904 INFO o.a.j.JMeter: Loaded icon properties from org/apache/jmeter/images/icon.properties
2022-12-02 14:38:40,004 INFO o.a.j.JMeterGuiLauncher: Setting LAF to: com.github.weisj.darklaf.DarkLaf:com.github.weisj.darklaf.theme.DarculaTheme
2022-12-02 14:38:40,147 ERROR o.a.j.JMeter: An error occurred: 
java.awt.HeadlessException: 
No X11 DISPLAY variable was set,
or no headful library support was found,
but this program performed an operation which requires it,

    at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:166) ~[?:?]
    at java.awt.Window.<init>(Window.java:553) ~[?:?]
    at java.awt.Frame.<init>(Frame.java:428) ~[?:?]
    at java.awt.Frame.<init>(Frame.java:393) ~[?:?]
    at javax.swing.SwingUtilities$SharedOwnerFrame.<init>(SwingUtilities.java:1919) ~[?:?]
    at javax.swing.SwingUtilities.getSharedOwnerFrame(SwingUtilities.java:1995) ~[?:?]
    at javax.swing.JDialog.<init>(JDialog.java:276) ~[?:?]
    at javax.swing.JDialog.<init>(JDialog.java:210) ~[?:?]
    at javax.swing.JDialog.<init>(JDialog.java:158) ~[?:?]
    at org.apache.jmeter.SplashScreen.<init>(SplashScreen.java:52) ~[ApacheJMeter_core.jar:5.5]
    at org.apache.jmeter.JMeterGuiLauncher.startGuiInternal(JMeterGuiLauncher.kt:87) ~[ApacheJMeter_core.jar:5.5]
    at org.apache.jmeter.JMeterGuiLauncher.access$startGuiInternal(JMeterGuiLauncher.kt:47) ~[ApacheJMeter_core.jar:5.5]
    at org.apache.jmeter.JMeterGuiLauncher$startGui$1$1.invokeSuspend(JMeterGuiLauncher.kt:67) ~[ApacheJMeter_core.jar:5.5]
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) ~[kotlin-stdlib-1.6.21.jar:1.6.21-release-334(1.6.21)]
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106) ~[kotlinx-coroutines-core-jvm-1.6.1.jar:?]
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318) ~[?:?]
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773) ~[?:?]
    at java.awt.EventQueue$4.run(EventQueue.java:720) ~[?:?]
    at java.awt.EventQueue$4.run(EventQueue.java:714) ~[?:?]
    at java.security.AccessController.doPrivileged(AccessController.java:399) ~[?:?]
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86) ~[?:?]
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:742) ~[?:?]
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203) ~[?:?]
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124) ~[?:?]
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113) ~[?:?]
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109) ~[?:?]
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) ~[?:?]
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:90) ~[?:?]

Ubuntu System Information

This particular issue seems to be because the DISPLAY environment variable isn't set. This can be fixed with the following

export DISPLAY=:0

You can check it worked with

echo $DISPLAY
# you should see :0

Bonus answer

But if the issue you really have is more like

An error occurred: Can't connect to X11 window server using ':0.0' as the value of the DISPLAY variable

The solution could be to ensure the x11 socket is available on the machine you are using.

In my case I was trying to get jmeter GUI running via a docker image. I was able to do it by ensuring the host and guest shared a read-writable volume at /tmp/.X11-unix:/tmp/.X11-unix

The issue is due to that you have multiple java versions.

Step1: Check version you have sudo dpkg --list | grep -i jdk . Also uninstall from software centre if you have open JDK

Step 2: Remove jdk sudo apt-get purge openjdk*

Step 3: Run in command line java -version, You will see no program is installed

Step4: Install sudo apt-get install openjdk-8-jre

JMeter should work now.