[BUG] Failed to create CEF browser

[jsfan3]

OS: Linux Mint 22
Java 17 CN1 Project

Code:

if (BrowserComponent.isNativeBrowserSupported()) {
    Log.p("Native Browser Supported");
    try {
        if (browser == null) {
            browser = new BrowserComponent();
            browser.setPinchToZoomEnabled(true);
            browser.setNativeScrollingEnabled(false);
        }
        browser.setPage(buildMapHtml(place), null);
        add(BorderLayout.CENTER, browser);
        browserShown = true;
    } catch (RuntimeException ex) {
        Log.e(ex);
        browser = null;
    }
}

Log:

/bin/sh ./mvnw -Didea.version=2026.1.1 -Dmaven.ext.class.path=/home/francesco/intellijIDEA/plugins/maven/lib/intellij.maven.rt/maven-event-listener.jar -Djansi.passthrough=true -Dstyle.color=always -P idea-simulator -Dcodename1.platform=javase -DskipTests=true -Dmaven.repo.local=/home/francesco/.m2/repository verify -e
WARNING: package com.apple.eawt not in java.desktop
[INFO] Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO] 
[INFO] dailyroutine                                                       [pom]
[INFO] dailyroutine-cn1libs                                               [pom]
[INFO] NativeLogsReader                                                   [pom]
[INFO] dailyroutine-common                                                [jar]
[INFO] dailyroutine-javase                                                [jar]
[INFO] 
[INFO] ---------------< com.baeldung.cn1tutorial:dailyroutine >----------------
[INFO] Building dailyroutine 1.0-SNAPSHOT                                 [1/5]
[INFO] --------------------------------[ pom ]---------------------------------
[INFO] 
[INFO] -----------< com.baeldung.cn1tutorial:dailyroutine-cn1libs >------------
[INFO] Building dailyroutine-cn1libs 1.0-SNAPSHOT                         [2/5]
[INFO] --------------------------------[ pom ]---------------------------------
[INFO] 
[INFO] -------< com.baeldung.cn1tutorial:dailyroutine-NativeLogsReader >-------
[INFO] Building NativeLogsReader 1.0-SNAPSHOT                             [3/5]
[INFO] --------------------------------[ pom ]---------------------------------
[INFO] 
[INFO] --- build-helper-maven-plugin:1.7:attach-artifact (attach-artifacts) @ dailyroutine-NativeLogsReader ---
[INFO] 
[INFO] ------------< com.baeldung.cn1tutorial:dailyroutine-common >------------
[INFO] Building dailyroutine-common 1.0-SNAPSHOT                          [4/5]
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- properties-maven-plugin:1.0.0:read-project-properties (default) @ dailyroutine-common ---
[INFO] 
[INFO] --- codenameone-maven-plugin:7.0.237:generate-gui-sources (generate-gui-sources) @ dailyroutine-common ---
Generating GUI sources
No GUI Entries available
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ dailyroutine-common ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 0 resource
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.0:compile (default-compile) @ dailyroutine-common ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 32 source files to /home/francesco/CN1 Tutorial/dailyroutine/common/target/classes
[INFO] /home/francesco/CN1 Tutorial/dailyroutine/common/src/main/java/com/baeldung/cn1tutorial/DailyRoutine.java: Some input files use unchecked or unsafe operations.
[INFO] /home/francesco/CN1 Tutorial/dailyroutine/common/src/main/java/com/baeldung/cn1tutorial/DailyRoutine.java: Recompile with -Xlint:unchecked for details.
[INFO] 
[INFO] --- codenameone-maven-plugin:7.0.237:compliance-check (cn1-process-classes) @ dailyroutine-common ---
[INFO] Running bytecode compliance check against Codename One Java Runtime API
[INFO] See https://www.codenameone.com/javadoc/ for supported Classes and Methods
[INFO] Invocation rewrite summary: classes rewritten=0, callsites rewritten=0
[INFO] 
[INFO] --- codenameone-maven-plugin:7.0.237:css (cn1-process-classes) @ dailyroutine-common ---
[INFO] CSS sources unchanged since last compile.  Skipping CSS compilation
[INFO] 
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ dailyroutine-common ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /home/francesco/CN1 Tutorial/dailyroutine/common/src/test/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.0:testCompile (default-testCompile) @ dailyroutine-common ---
[INFO] Nothing to compile - all classes are up to date
[INFO] 
[INFO] --- maven-surefire-plugin:3.0.0-M5:test (default-test) @ dailyroutine-common ---
[INFO] Tests are skipped.
[INFO] 
[INFO] --- codenameone-maven-plugin:7.0.237:attach-test-artifact (attach-test-artifact) @ dailyroutine-common ---
[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ dailyroutine-common ---
[INFO] Building jar: /home/francesco/CN1 Tutorial/dailyroutine/common/target/dailyroutine-common-1.0-SNAPSHOT.jar
[INFO] 
[INFO] ------------< com.baeldung.cn1tutorial:dailyroutine-javase >------------
[INFO] Building dailyroutine-javase 1.0-SNAPSHOT                          [5/5]
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- codenameone-maven-plugin:7.0.237:prepare-simulator-classpath (prepare-simulator-environment) @ dailyroutine-javase ---
[INFO] Preparing Simulator Classpath
[INFO] 
[INFO] --- codenameone-maven-plugin:7.0.237:generate-javase-sources (add-se-sources) @ dailyroutine-javase ---
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ dailyroutine-javase ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /home/francesco/CN1 Tutorial/dailyroutine/javase/src/main/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.0:compile (default-compile) @ dailyroutine-javase ---
[INFO] Nothing to compile - all classes are up to date
[INFO] 
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ dailyroutine-javase ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /home/francesco/CN1 Tutorial/dailyroutine/javase/src/test/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.0:testCompile (default-testCompile) @ dailyroutine-javase ---
[INFO] Nothing to compile - all classes are up to date
[INFO] 
[INFO] --- maven-surefire-plugin:3.0.0-M5:test (default-test) @ dailyroutine-javase ---
[INFO] Tests are skipped.
[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ dailyroutine-javase ---
[INFO] 
[INFO] --- exec-maven-plugin:3.0.0:java (run-in-simulator-idea) @ dailyroutine-javase ---
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Adding CEF to classpath
Retina Scale: 1.0
Adding watch folder /home/francesco/CN1 Tutorial/dailyroutine/common/src/main/java
Did not find hotswap-agent.properties file
SourceChangeWatcher running.  Watching directories [/home/francesco/CN1 Tutorial/dailyroutine/common/src/main/java]
Starting CSS Watcher for prefix 
Watching CSS files for changes: [/home/francesco/CN1 Tutorial/dailyroutine/javase/../common/src/main/css/theme.css]
Running CSS watch with args [/usr/lib/jvm/java-21-openjdk-amd64/bin/java, -jar, -Dcli=true, -Dcef.dir=/home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted, -Dparent.port=46003, /home/francesco/.m2/repository/com/codenameone/codenameone-designer/7.0.237/codenameone-designer-7.0.237-jar-with-dependencies.jar-extracted/designer_1.jar, -css, -input, /home/francesco/CN1 Tutorial/dailyroutine/javase/../common/src/main/css/theme.css, -output, /home/francesco/CN1 Tutorial/dailyroutine/javase/../common/target/classes/theme.res, -merge, /home/francesco/CN1 Tutorial/dailyroutine/javase/../common/target/css/theme.css, -l, /home/francesco/CN1 Tutorial/dailyroutine/javase/../common/src/main/l10n, -watch]
CSS> Retina Scale: 1.0
CSS> Using stateless mode
CSS> Looks like this CSS file needs CEF on classpath... adding it now, and retrying...
CSS> Adding CEF to classpath /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted
CSS> SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
CSS> SLF4J: Defaulting to no-operation (NOP) logger implementation
CSS> SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
CSS> Retina Scale: 1.0
CSS> Using stateless mode
CSS> Updating merge file /home/francesco/CN1 Tutorial/dailyroutine/javase/../common/target/css/theme.css
CSS> Starting watch thread to watch [/home/francesco/CN1 Tutorial/dailyroutine/javase/../common/src/main/css/theme.css]
CSS> Compiling /home/francesco/CN1 Tutorial/dailyroutine/javase/../common/target/css/theme.css to /home/francesco/CN1 Tutorial/dailyroutine/javase/../common/target/classes/theme.res
CSS> File has not changed since last compile.
CSS> CSS file successfully compiled.  /home/francesco/CN1 Tutorial/dailyroutine/javase/../common/target/classes/theme.res
[EDT] 0:0:20,194 - Codename One revisions: 7dd4e7d08b3442d90959477ee52a5ae8c4361b29

[EDT] 0:0:20,194 - Native Browser Supported
[EDT] 0:0:20,209 - Attempting to create browser component
[AWT-EventQueue-0] 0:0:20,211 - Attempting to create browser component
[EDT] 0:0:20,234 - Exception: java.lang.UnsatisfiedLinkError - /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjcef.so: /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjawt.so: version `SUNWprivate_1.1' not found (required by /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjcef.so)
[EDT] 0:0:20,235 - Exception: java.lang.RuntimeException - Failed to create CEF browser
[EDT] 0:0:20,236 - Exception: java.lang.RuntimeException - Failed to create CEF browser
java.lang.UnsatisfiedLinkError: /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjcef.so: /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjawt.so: version `SUNWprivate_1.1' not found (required by /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjcef.so)
	at java.base/jdk.internal.loader.NativeLibraries.load(Native Method)
	at java.base/jdk.internal.loader.NativeLibraries$NativeLibraryImpl.open(NativeLibraries.java:331)
	at java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:197)
	at java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:139)
	at java.base/java.lang.ClassLoader.loadLibrary(ClassLoader.java:2444)
	at java.base/java.lang.Runtime.loadLibrary0(Runtime.java:916)
	at java.base/java.lang.System.loadLibrary(System.java:2063)
	at org.cef.SystemBootstrap$1.loadLibrary(SystemBootstrap.java:24)
	at org.cef.SystemBootstrap.loadLibrary(SystemBootstrap.java:36)
	at org.cef.CefApp.startup(CefApp.java:536)
	at com.codename1.impl.javase.cef.CEFBrowserComponent.create(CEFBrowserComponent.java:212)
	at com.codename1.impl.javase.cef.CEFBrowserComponent.create(CEFBrowserComponent.java:204)
	at com.codename1.impl.javase.cef.CEFBrowserComponent.create(CEFBrowserComponent.java:201)
	at com.codename1.impl.javase.cef.JavaCEFSEPort.createCEFBrowserComponent(JavaCEFSEPort.java:139)
	at com.codename1.impl.javase.cef.JavaCEFSEPort$2.run(JavaCEFSEPort.java:121)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:308)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
java.lang.RuntimeException: Failed to create CEF browser
	at com.codename1.impl.javase.cef.JavaCEFSEPort.createCEFBrowserComponent(JavaCEFSEPort.java:133)
	at com.codename1.impl.javase.cef.JavaCEFSEPort.createBrowserComponent(JavaCEFSEPort.java:98)
	at com.codename1.ui.BrowserComponent$1.run(BrowserComponent.java:156)
	at com.codename1.ui.Display.executeSerialCall(Display.java:1296)
	at com.codename1.ui.Display.processSerialCalls(Display.java:1280)
	at com.codename1.ui.Display.edtLoopImpl(Display.java:1223)
	at com.codename1.ui.Display.mainEDTLoop(Display.java:1076)
	at com.codename1.ui.RunnableWrapper.run(RunnableWrapper.java:139)
	at com.codename1.impl.CodenameOneThread.run(CodenameOneThread.java:179)
Caused by: java.lang.UnsatisfiedLinkError: /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjcef.so: /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjawt.so: version `SUNWprivate_1.1' not found (required by /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjcef.so)
	at java.base/jdk.internal.loader.NativeLibraries.load(Native Method)
	at java.base/jdk.internal.loader.NativeLibraries$NativeLibraryImpl.open(NativeLibraries.java:331)
	at java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:197)
	at java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:139)
	at java.base/java.lang.ClassLoader.loadLibrary(ClassLoader.java:2444)
	at java.base/java.lang.Runtime.loadLibrary0(Runtime.java:916)
	at java.base/java.lang.System.loadLibrary(System.java:2063)
	at org.cef.SystemBootstrap$1.loadLibrary(SystemBootstrap.java:24)
	at org.cef.SystemBootstrap.loadLibrary(SystemBootstrap.java:36)
	at org.cef.CefApp.startup(CefApp.java:536)
	at com.codename1.impl.javase.cef.CEFBrowserComponent.create(CEFBrowserComponent.java:212)
	at com.codename1.impl.javase.cef.CEFBrowserComponent.create(CEFBrowserComponent.java:204)
	at com.codename1.impl.javase.cef.CEFBrowserComponent.create(CEFBrowserComponent.java:201)
	at com.codename1.impl.javase.cef.JavaCEFSEPort.createCEFBrowserComponent(JavaCEFSEPort.java:139)
	at com.codename1.impl.javase.cef.JavaCEFSEPort$2.run(JavaCEFSEPort.java:121)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:308)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
java.lang.RuntimeException: Failed to create CEF browser
	at com.codename1.impl.javase.cef.JavaCEFSEPort.createCEFBrowserComponent(JavaCEFSEPort.java:133)
	at com.codename1.impl.javase.cef.JavaCEFSEPort.createBrowserComponent(JavaCEFSEPort.java:98)
	at com.codename1.ui.BrowserComponent$1.run(BrowserComponent.java:156)
	at com.codename1.ui.Display.executeSerialCall(Display.java:1296)
	at com.codename1.ui.Display.processSerialCalls(Display.java:1280)
	at com.codename1.ui.Display.edtLoopImpl(Display.java:1223)
	at com.codename1.ui.Display.mainEDTLoop(Display.java:1076)
	at com.codename1.ui.RunnableWrapper.run(RunnableWrapper.java:139)
	at com.codename1.impl.CodenameOneThread.run(CodenameOneThread.java:179)
Caused by: java.lang.UnsatisfiedLinkError: /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjcef.so: /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjawt.so: version `SUNWprivate_1.1' not found (required by /home/francesco/.m2/repository/com/codenameone/codenameone-cef/84.4.1-M3/codenameone-cef-84.4.1-M3-linux64.zip-extracted/lib/linux64/libjcef.so)
	at java.base/jdk.internal.loader.NativeLibraries.load(Native Method)
	at java.base/jdk.internal.loader.NativeLibraries$NativeLibraryImpl.open(NativeLibraries.java:331)
	at java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:197)
	at java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:139)
	at java.base/java.lang.ClassLoader.loadLibrary(ClassLoader.java:2444)
	at java.base/java.lang.Runtime.loadLibrary0(Runtime.java:916)
	at java.base/java.lang.System.loadLibrary(System.java:2063)
	at org.cef.SystemBootstrap$1.loadLibrary(SystemBootstrap.java:24)
	at org.cef.SystemBootstrap.loadLibrary(SystemBootstrap.java:36)
	at org.cef.CefApp.startup(CefApp.java:536)
	at com.codename1.impl.javase.cef.CEFBrowserComponent.create(CEFBrowserComponent.java:212)
	at com.codename1.impl.javase.cef.CEFBrowserComponent.create(CEFBrowserComponent.java:204)
	at com.codename1.impl.javase.cef.CEFBrowserComponent.create(CEFBrowserComponent.java:201)
	at com.codename1.impl.javase.cef.JavaCEFSEPort.createCEFBrowserComponent(JavaCEFSEPort.java:139)
	at com.codename1.impl.javase.cef.JavaCEFSEPort$2.run(JavaCEFSEPort.java:121)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:308)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

[jsfan3]

I was able to resolve this issue on Linux, so here is the diagnosis in case it helps.

I added detailed environment logging in init() using CN.getProperty(key, "<unset>"). I got:

java.version=21.0.10
java.vendor=Ubuntu
java.runtime.name=OpenJDK Runtime Environment
java.runtime.version=21.0.10+7-Ubuntu-124.04
java.vm.name=OpenJDK 64-Bit Server VM
java.vm.version=21.0.10+7-Ubuntu-124.04
java.home=/usr/lib/jvm/java-21-openjdk-amd64
etc.

That’s how my attention turned to:

[...]
JAVA_HOME=<unset>
[...]
LD_LIBRARY_PATH=<unset>
[...]

So, in my case, a practical workaround was to create this launcher.sh for Intellij IDEA:

#!/bin/bash
cd ~/intellijIDEA/bin
export JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64
export LD_LIBRARY_PATH=$JAVA_HOME/lib:$JAVA_HOME/lib/server${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}
./idea

Note that I specified the path to Java 17 even though the java.runtime.version and java.vm.version entries in the log show Java 21. I'm not sure if it was really necessary, but it solved the exception.

That's all. Even with this launcher, the two environment variables are still printed as unset; however, the BrowserComponent now works fine in the Simulator, and the java.lang.RuntimeException - Failed to create CEF browser exception has disappeared.

Perhaps what I've written here will help others as well. At this point I would consider it a workaround rather than a real explanation of the root cause.

@shai-almog, do you think it would be worth adding a small warning or troubleshooting note to the official Codename One documentation in the BrowserComponent section? For example, in case of problems on Linux, it might be useful to suggest checking the Java runtime and launch environment. https://www.codenameone.com/developer-guide/#_browsercomponent_webbrowser