Linux error when launching

Hello,
For a few days now, I can’t start Ganttproject on my linux computer.
I’m using Ubuntu 18.04 LTS x64. It’s up to date.
Here’s what I got when I try launching Ganttproject on a console window :

ASUS:~$ ganttproject 
ASUS:~$ août 27, 2018 11:23:52 AM org.bardsoftware.impl.eclipsito.BootImpl$1 uncaughtException
AVERTISSEMENT: [uncaughtException]java.awt.AWTError: Assistive Technology not found: org.GNOME.Accessibility.AtkWrapper
java.awt.AWTError: Assistive Technology not found: org.GNOME.Accessibility.AtkWrapper
    at java.desktop/java.awt.Toolkit.newAWTError(Toolkit.java:472)
    at java.desktop/java.awt.Toolkit.fallbackToLoadClassForAT(Toolkit.java:488)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
    at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
    at java.base/java.util.HashMap$KeySpliterator.forEachRemaining(HashMap.java:1608)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
    at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
    at java.desktop/java.awt.Toolkit.loadAssistiveTechnologies(Toolkit.java:532)
    at java.desktop/java.awt.Toolkit.getDefaultToolkit(Toolkit.java:613)
    at java.desktop/sun.swing.SwingUtilities2.getSystemMnemonicKeyMask(SwingUtilities2.java:2143)
    at java.desktop/javax.swing.plaf.basic.BasicLookAndFeel.initComponentDefaults(BasicLookAndFeel.java:1096)
    at java.desktop/javax.swing.plaf.metal.MetalLookAndFeel.initComponentDefaults(MetalLookAndFeel.java:440)
    at java.desktop/javax.swing.plaf.basic.BasicLookAndFeel.getDefaults(BasicLookAndFeel.java:150)
    at java.desktop/javax.swing.plaf.metal.MetalLookAndFeel.getDefaults(MetalLookAndFeel.java:1560)
    at java.desktop/javax.swing.UIManager.setLookAndFeel(UIManager.java:587)
    at java.desktop/javax.swing.UIManager.setLookAndFeel(UIManager.java:628)
    at java.desktop/javax.swing.UIManager.initializeDefaultLAF(UIManager.java:1403)
    at java.desktop/javax.swing.UIManager.initialize(UIManager.java:1516)
    at java.desktop/javax.swing.UIManager.maybeInitialize(UIManager.java:1482)
    at java.desktop/javax.swing.UIManager.getDefaults(UIManager.java:708)
    at java.desktop/javax.swing.UIManager.put(UIManager.java:1037)
    at net.sourceforge.ganttproject.language.GanttLanguage.setShortDateFormat(GanttLanguage.java:175)
    at net.sourceforge.ganttproject.language.GanttLanguage.applyDateFormatLocale(GanttLanguage.java:162)
    at net.sourceforge.ganttproject.language.GanttLanguage.setLocale(GanttLanguage.java:189)
    at net.sourceforge.ganttproject.language.GanttLanguage.<init>(GanttLanguage.java:133)
    at net.sourceforge.ganttproject.language.GanttLanguage.<clinit>(GanttLanguage.java:94)
    at net.sourceforge.ganttproject.GanttProjectBase.<clinit>(GanttProjectBase.java:83)
    at net.sourceforge.ganttproject.application.MainApplication.run(MainApplication.java:36)
    at org.bardsoftware.impl.eclipsito.ApplicationLauncher.launchApplication(ApplicationLauncher.java:29)
    at org.bardsoftware.impl.eclipsito.BootImpl$2.run(BootImpl.java:50)
Caused by: java.lang.ClassNotFoundException: org.GNOME.Accessibility.AtkWrapper
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:190)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)
    at java.base/java.lang.Class.forName0(Native Method)
    at java.base/java.lang.Class.forName(Class.java:374)
    at java.desktop/java.awt.Toolkit.fallbackToLoadClassForAT(Toolkit.java:485)
    ... 32 more

août 27, 2018 11:23:52 AM org.bardsoftware.impl.eclipsito.BootImpl$1 uncaughtException
AVERTISSEMENT: [uncaughtException]java.awt.AWTError: Assistive Technology not found: org.GNOME.Accessibility.AtkWrapper
java.awt.AWTError: Assistive Technology not found: org.GNOME.Accessibility.AtkWrapper
    at java.desktop/java.awt.Toolkit.newAWTError(Toolkit.java:472)
    at java.desktop/java.awt.Toolkit.fallbackToLoadClassForAT(Toolkit.java:488)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
    at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
    at java.base/java.util.HashMap$KeySpliterator.forEachRemaining(HashMap.java:1608)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
    at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
    at java.desktop/java.awt.Toolkit.loadAssistiveTechnologies(Toolkit.java:532)
    at java.desktop/java.awt.Toolkit.getDefaultToolkit(Toolkit.java:613)
    at java.desktop/sun.swing.SwingUtilities2.getSystemMnemonicKeyMask(SwingUtilities2.java:2143)
    at java.desktop/javax.swing.plaf.basic.BasicLookAndFeel.initComponentDefaults(BasicLookAndFeel.java:1096)
    at java.desktop/javax.swing.plaf.metal.MetalLookAndFeel.initComponentDefaults(MetalLookAndFeel.java:440)
    at java.desktop/javax.swing.plaf.basic.BasicLookAndFeel.getDefaults(BasicLookAndFeel.java:150)
    at java.desktop/javax.swing.plaf.metal.MetalLookAndFeel.getDefaults(MetalLookAndFeel.java:1560)
    at java.desktop/javax.swing.UIManager.setLookAndFeel(UIManager.java:587)
    at java.desktop/javax.swing.UIManager.setLookAndFeel(UIManager.java:628)
    at java.desktop/javax.swing.UIManager.initializeDefaultLAF(UIManager.java:1403)
    at java.desktop/javax.swing.UIManager.initialize(UIManager.java:1516)
    at java.desktop/javax.swing.UIManager.maybeInitialize(UIManager.java:1482)
    at java.desktop/javax.swing.UIManager.getDefaults(UIManager.java:708)
    at java.desktop/javax.swing.UIManager.put(UIManager.java:1037)
    at net.sourceforge.ganttproject.language.GanttLanguage.setShortDateFormat(GanttLanguage.java:175)
    at net.sourceforge.ganttproject.language.GanttLanguage.applyDateFormatLocale(GanttLanguage.java:162)
    at net.sourceforge.ganttproject.language.GanttLanguage.setLocale(GanttLanguage.java:189)
    at net.sourceforge.ganttproject.language.GanttLanguage.<init>(GanttLanguage.java:133)
    at net.sourceforge.ganttproject.language.GanttLanguage.<clinit>(GanttLanguage.java:94)
    at net.sourceforge.ganttproject.GanttProjectBase.<clinit>(GanttProjectBase.java:83)
    at net.sourceforge.ganttproject.application.MainApplication.run(MainApplication.java:36)
    at org.bardsoftware.impl.eclipsito.ApplicationLauncher.launchApplication(ApplicationLauncher.java:29)
    at org.bardsoftware.impl.eclipsito.BootImpl$2.run(BootImpl.java:50)
Caused by: java.lang.ClassNotFoundException: org.GNOME.Accessibility.AtkWrapper
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:190)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)
    at java.base/java.lang.Class.forName0(Native Method)
    at java.base/java.lang.Class.forName(Class.java:374)
    at java.desktop/java.awt.Toolkit.fallbackToLoadClassForAT(Toolkit.java:485)
    ... 32 more

Any idea what could solve this?
Cheers,
alex

Solved with :

First remove conflicting java packages:

sudo apt-get remove --purge openjdk* java-common default-jdk
sudo apt-get autoremove --purge

Check weather you successfully removed all related packages by:

sudo update-alternatives --config java

The system shall prompt you there is no Java available to config, otherwise this workaround fails.

Then reinstall required packages:

sudo apt-get install openjdk-8-jdk

Thanks to shvahabi