Android Studio preview: This JVM does not support constant tag 15

Question

I'm attempting to look at a preview of an xml layout that contains a couple custom views (nothing complicated... mostly wrappers). I'm getting the following error:

The following classes could not be instantiated:
- com.app.view.widget.SlidingSwipeRefreshLayout (Open Class, Show Exception, Clear Cache)
- com.app.view.widget.BetterViewAnimator (Open Class, Show Exception, Clear Cache)

java.lang.ClassFormatError: This JVM does not support constant tag 15 in class file <Unknown>
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:471)
    at com.android.tools.idea.rendering.RenderClassLoader.loadClass(RenderClassLoader.java:150)
    at com.android.tools.idea.rendering.RenderClassLoader.loadClassFile(RenderClassLoader.java:125)
    at org.jetbrains.android.uipreview.ModuleClassLoader.loadClassFile(ModuleClassLoader.java:287)
    at com.android.tools.idea.rendering.RenderClassLoader.loadClassFromClassPath(RenderClassLoader.java:118)
    at org.jetbrains.android.uipreview.ModuleClassLoader.loadClassFromModule(ModuleClassLoader.java:202)
    at org.jetbrains.android.uipreview.ModuleClassLoader.loadClassFromModuleOrDependency(ModuleClassLoader.java:136)
    at org.jetbrains.android.uipreview.ModuleClassLoader.load(ModuleClassLoader.java:122)
    at com.android.tools.idea.rendering.RenderClassLoader.findClass(RenderClassLoader.java:53)
    at org.jetbrains.android.uipreview.ModuleClassLoader.findClass(ModuleClassLoader.java:84)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.java:182)
    at org.jetbrains.android.uipreview.ViewLoader.loadView(ViewLoader.java:101)
    at com.android.tools.idea.rendering.LayoutlibCallback.loadView(LayoutlibCallback.java:177)
    at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:207)
    at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:132)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:482)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:385)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:400)
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:332)
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:350)
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:497)
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:485)
    at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:894)
    at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:485)
    at com.android.tools.idea.rendering.RenderTask.render(RenderTask.java:590)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.doRender(AndroidLayoutPreviewToolWindowManager.java:644)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.access$1700(AndroidLayoutPreviewToolWindowManager.java:79)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7$1.run(AndroidLayoutPreviewToolWindowManager.java:586)
    at com.intellij.openapi.progress.impl.CoreProgressManager$2.run(CoreProgressManager.java:152)
    at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:452)
    at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:402)
    at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:54)
    at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:137)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7.run(AndroidLayoutPreviewToolWindowManager.java:581)
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:320)
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:310)
    at com.intellij.util.ui.update.MergingUpdateQueue$2.run(MergingUpdateQueue.java:254)
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:269)
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:227)
    at com.intellij.util.ui.update.MergingUpdateQueue.run(MergingUpdateQueue.java:217)
    at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.java:238)
    at com.intellij.util.Alarm$Request$1.run(Alarm.java:351)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:439)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
    at java.lang.Thread.run(Thread.java:695)

Is there a suggested fix for it? I've tried the typical cleaning/re-building and restarting Android Studio.

Answer 1

If you have lambdas in your custom view class, then you need to run Android Studio under Java 8. According to tools.android.com, you can do this by setting the STUDIO_JDK environment variable.

If you are on a Mac, you can set this environment variable so that it is always used by Android Studio by running the following:

launchctl setenv STUDIO_JDK /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk

(Adjust according to your actual JDK location.)