Exception in editor mode (preview not work)

The following classes could not be instantiated: - com.prolificinteractive.materialcalendarview.MaterialCalendarView

java.lang.NullPointerException
	at com.prolificinteractive.materialcalendarview.MaterialCalendarView.setupChildren(MaterialCalendarView.java:425)
	at com.prolificinteractive.materialcalendarview.MaterialCalendarView.<init>(MaterialCalendarView.java:404)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at org.jetbrains.android.uipreview.ViewLoader.createNewInstance(ViewLoader.java:401)
	at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.java:184)
	at org.jetbrains.android.uipreview.ViewLoader.loadView(ViewLoader.java:142)
	at com.android.tools.idea.rendering.LayoutlibCallbackImpl.loadView(LayoutlibCallbackImpl.java:229)
	at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:421)
	at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:432)
	at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:336)
	at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
	at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:863)
	at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:72)
	at android.view.LayoutInflater.rInflate(LayoutInflater.java:837)
	at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
	at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
	at android.view.LayoutInflater.inflate(LayoutInflater.java:394)
	at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:327)
	at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:386)
	at com.android.tools.idea.layoutlib.LayoutLibrary.createSession(LayoutLibrary.java:193)
	at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:450)
	at com.android.tools.idea.rendering.RenderTask.lambda$inflate$3(RenderTask.java:590)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)

[pdaniel37]

Same here (edit) i solved problem for me, using version 1.6.0 instead of 2.0.1, curiously 1.6.1 and above not works (had the same problem)

[MacStevins]

So, I discovered the fix on the Design Editor problem.

I downloaded the source code and opened up Android Studio. Then I tried to separate the calendarMode variable from the state builder, then instantiate it like this; calendarMode = CalendarMode.values()[calendarModeIndex];

Then I built the project, and a org.threeten.bp.zone.ZoneRulesException: No time-zone data files registered occurred, and googled about that exception and found this.

After finding the answer, adding the missing statement, and returning the state builder back. A new exception popped up (As of writing this, it didn’t occurred, but it did happened);

java.lang.NullPointerException at com.prolificinteractive.materialcalendarview.TitleChanger.change(TitleChanger.java:59)

So I tried to add a != null on the if statement, and it worked!

I don’t know if this is breaking the license or something, but alot of people including me is having this problem, but I’m not gonna use my version of the library and I’m gonna wait for the update.