"All Swing components and related classes, unless otherwise documented, must be accessed on the event dispatching thread."

http://docs.oracle.com/javase/8/docs/api/javax/swing/package-summary.html

java-atk-wrapper breaks this rule. For instance, the AtkText's ctor:

       public AtkText (AccessibleContext ac) {
                super();
                this.ac = ac;
                this.acc_text = ac.getAccessibleText();
       }

It calls a method right on an AccessibleContext object, whereas the ctor itself is called from:

jawtext.c: jaw_text_data_init

That is, from the java-atk-wrapper main thread.

Some apps rely on the Swing threading rule (for instance, in their synchronization model) and can be strict about following it. One of such apps is IntelliJ IDEA Java IDE, which throws exceptions like the following:

Read access is allowed from event dispatch thread or inside read-action only (see com.intellij.openapi.application.Application.runReadAction())
Details: Current thread: Thread[Thread-1,5,main] 1276501196
; dispatch thread: false; isDispatchThread(): false
SystemEventQueueThread: Thread[AWT-EventQueue-1 15.0#IC-143.379.11, eap:true,6,main] 927664267


java.lang.Throwable
	at com.intellij.openapi.diagnostic.Logger.error(Logger.java:126)
	at com.intellij.openapi.application.impl.ApplicationImpl.assertReadAccessAllowed(ApplicationImpl.java:1047)
	at com.intellij.util.indexing.FileBasedIndexImpl.ensureUpToDate(FileBasedIndexImpl.java:810)
	at com.intellij.util.indexing.FileBasedIndexImpl.ensureUpToDate(FileBasedIndexImpl.java:801)
	at com.intellij.psi.stubs.StubIndexImpl.doProcessStubs(StubIndexImpl.java:242)
	at com.intellij.psi.stubs.StubIndexImpl.processElements(StubIndexImpl.java:223)
	at com.intellij.psi.stubs.StubIndex.getElements(StubIndex.java:145)
	at com.intellij.psi.stubs.StubIndex.getElements(StubIndex.java:135)
	at com.intellij.psi.impl.java.stubs.index.JavaFullClassNameIndex.get(JavaFullClassNameIndex.java:48)
	at com.intellij.psi.impl.file.impl.JavaFileManagerImpl.findClassInIndex(JavaFileManagerImpl.java:122)
	at com.intellij.psi.impl.file.impl.JavaFileManagerImpl.findClass(JavaFileManagerImpl.java:115)
	at com.intellij.psi.impl.PsiElementFinderImpl.findClass(PsiElementFinderImpl.java:54)
	at com.intellij.psi.impl.JavaPsiFacadeImpl.doFindClass(JavaPsiFacadeImpl.java:124)
	at com.intellij.psi.impl.JavaPsiFacadeImpl.findClass(JavaPsiFacadeImpl.java:101)
	at com.intellij.execution.JavaExecutionUtil.findMainClass(JavaExecutionUtil.java:178)
	at com.intellij.execution.JavaExecutionUtil.findMainClass(JavaExecutionUtil.java:168)
	at com.intellij.execution.util.JavaParametersUtil.isClassInProductionSources(JavaParametersUtil.java:94)
	at com.intellij.execution.ui.DefaultJreSelectorKt.isClassInProductionSources(DefaultJreSelector.kt:115)
	at com.intellij.execution.ui.DefaultJreSelectorKt.access$isClassInProductionSources(DefaultJreSelector.kt:1)
	at com.intellij.execution.ui.DefaultJreSelector$SdkFromSourceRootDependencies$1.invoke(DefaultJreSelector.kt:100)
	at com.intellij.execution.ui.DefaultJreSelector$SdkFromSourceRootDependencies$1.invoke(DefaultJreSelector.kt:99)
	at com.intellij.execution.ui.DefaultJreSelector$SdkFromModuleDependencies.getNameAndDescription(DefaultJreSelector.kt:82)
	at com.intellij.execution.ui.DefaultJreSelector.getDescriptionString(DefaultJreSelector.kt:69)
	at com.intellij.execution.ui.JrePathEditor$DefaultJreItem.render(JrePathEditor.java:275)
	at com.intellij.execution.ui.JrePathEditor$2.doCustomize(JrePathEditor.java:111)
	at com.intellij.execution.ui.JrePathEditor$2.doCustomize(JrePathEditor.java:108)
	at com.intellij.ui.ColoredListCellRendererWrapper.customizeCellRenderer(ColoredListCellRendererWrapper.java:29)
	at com.intellij.ui.ColoredListCellRenderer.getListCellRendererComponent(ColoredListCellRenderer.java:75)
	at com.intellij.openapi.ui.ComboBoxWithWidePopup$AdjustingListCellRenderer.getListCellRendererComponent(ComboBoxWithWidePopup.java:120)
	at javax.swing.JList$AccessibleJList$AccessibleJListChild.getComponentAtIndex(JList.java:3227)
	at javax.swing.JList$AccessibleJList$AccessibleJListChild.getCurrentAccessibleContext(JList.java:3208)
	at javax.swing.JList$AccessibleJList$AccessibleJListChild.getAccessibleText(JList.java:3394)
	at org.GNOME.Accessibility.AtkText.<init>(AtkText.java:47)