Android Studio Error Solution: Please change caller according to ......

Error: Please
change caller according to com.intellij.openapi.project.IndexNotReadyException documentation

if you find this error on your android, you just restart Android Studio. Then you will not find that the error has disappered. :)

Please change caller according to com.intellij.openapi.project.IndexNotReadyException documentation
com.intellij.openapi.project.IndexNotReadyException: Please change caller according to com.intellij.openapi.project.IndexNotReadyException documentation
at com.intellij.util.indexing.FileBasedIndexImpl.handleDumbMode(FileBasedIndexImpl.java:853)
at com.intellij.util.indexing.FileBasedIndexImpl.ensureUpToDate(FileBasedIndexImpl.java:802)
at com.intellij.util.indexing.FileBasedIndexImpl.ensureUpToDate(FileBasedIndexImpl.java:786)
at com.intellij.psi.stubs.StubIndexImpl.processElements(StubIndexImpl.java:250)
at com.intellij.psi.stubs.StubIndexImpl.processElements(StubIndexImpl.java:238)
at com.intellij.psi.stubs.StubIndex.process(StubIndex.java:76)
at com.intellij.psi.stubs.StubIndex.process(StubIndex.java:95)
at com.intellij.psi.stubs.StubIndexImpl.get(StubIndexImpl.java:227)
at com.intellij.psi.stubs.StubIndex.getElements(StubIndex.java:144)
at com.intellij.psi.stubs.StubIndex.getElements(StubIndex.java:134)
at com.intellij.psi.impl.java.stubs.index.JavaFullClassNameIndex.get(JavaFullClassNameIndex.java:48)
at com.intellij.psi.impl.file.impl.JavaFileManagerImpl.findClassInIndex(JavaFileManagerImpl.java:145)
at com.intellij.psi.impl.file.impl.JavaFileManagerImpl.findClass(JavaFileManagerImpl.java:138)
at com.intellij.psi.impl.PsiElementFinderImpl.findClass(PsiElementFinderImpl.java:54)
at com.intellij.psi.impl.JavaPsiFacadeImpl.findClass(JavaPsiFacadeImpl.java:102)
at org.jetbrains.android.dom.converters.PackageClassConverter.fromString(PackageClassConverter.java:88)
at org.jetbrains.android.dom.converters.PackageClassConverter.fromString(PackageClassConverter.java:47)
at com.intellij.util.xml.impl.GetInvocation.getValueInner(GetInvocation.java:102)
at com.intellij.util.xml.impl.GetInvocation.getOrCalcValue(GetInvocation.java:77)
at com.intellij.util.xml.impl.GetInvocation.invoke(GetInvocation.java:65)
at com.intellij.util.xml.impl.DomInvocationHandler.invoke(DomInvocationHandler.java:689)
at org.jetbrains.android.dom.AndroidAttributeValue$$EnhancerByCGLIB$$ce3af24b.getValue(<generated>)
at org.jetbrains.android.run.ActivityLocatorUtils.getQualifiedName(ActivityLocatorUtils.java:80)
at org.jetbrains.android.run.DefaultActivityLocator$RealActivityWrapper.getQualifiedName(DefaultActivityLocator.java:215)
at org.jetbrains.android.run.DefaultActivityLocator.computeDefaultActivity(DefaultActivityLocator.java:100)
at org.jetbrains.android.run.DefaultActivityLocator.access$000(DefaultActivityLocator.java:36)
at org.jetbrains.android.run.DefaultActivityLocator$2.compute(DefaultActivityLocator.java:86)
at org.jetbrains.android.run.DefaultActivityLocator$2.compute(DefaultActivityLocator.java:78)
at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:884)
at org.jetbrains.android.run.DefaultActivityLocator.getDefaultLauncherActivityName(DefaultActivityLocator.java:78)
at org.jetbrains.android.facet.AndroidFrameworkDetector.doImportSdkAndFacetConfiguration(AndroidFrameworkDetector.java:133)
at org.jetbrains.android.facet.AndroidFrameworkDetector$1.run(AndroidFrameworkDetector.java:93)
at com.intellij.ide.startup.impl.StartupManagerImpl$7.run(StartupManagerImpl.java:369)
at com.intellij.util.ui.UIUtil.invokeLaterIfNeeded(UIUtil.java:2350)
at com.intellij.ide.startup.impl.StartupManagerImpl.runWhenProjectIsInitialized(StartupManagerImpl.java:365)
at org.jetbrains.android.facet.AndroidFrameworkDetector.setupFacet(AndroidFrameworkDetector.java:90)
at org.jetbrains.android.facet.AndroidFrameworkDetector.setupFacet(AndroidFrameworkDetector.java:60)
at com.intellij.framework.detection.impl.FacetBasedDetectedFrameworkDescription.doSetup(FacetBasedDetectedFrameworkDescription.java:119)
at com.intellij.framework.detection.impl.FacetBasedDetectedFrameworkDescriptionImpl.setupFramework(FacetBasedDetectedFrameworkDescriptionImpl.java:53)
at com.intellij.framework.detection.impl.FrameworkDetectionUtil.setupFrameworks(FrameworkDetectionUtil.java:104)
at com.intellij.framework.detection.impl.FrameworkDetectionManager.showSetupFrameworksDialog(FrameworkDetectionManager.java:258)
at com.intellij.framework.detection.impl.FrameworkDetectionManager.access$500(FrameworkDetectionManager.java:59)
at com.intellij.framework.detection.impl.FrameworkDetectionManager$4.hyperlinkUpdate(FrameworkDetectionManager.java:200)
at com.intellij.notification.impl.ui.NotificationsUtil$1.hyperlinkUpdate(NotificationsUtil.java:75)
at javax.swing.JEditorPane.fireHyperlinkUpdate(JEditorPane.java:345)
at javax.swing.text.html.HTMLEditorKit$LinkController.activateLink(HTMLEditorKit.java:877)
at javax.swing.text.html.HTMLEditorKit$LinkController.mouseClicked(HTMLEditorKit.java:676)
at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:270)
at java.awt.Component.processMouseEvent(Component.java:6508)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3320)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4501)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:734)
at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:565)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:382)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)