[Bug] FilePicker throws System.InvalidOperationException: 'Window Not Found'

Description

In maui preview7 on android, whenever call FilePicker.PickAsync(); method the maui application will throw System.InvalidOperationException: 'Window Not Found' and crash.

Steps to Reproduce

1. create a new maui app using default maui templat
2. setup permissions and call platform init on android
3. add await FilePicker.PickAsync(); in button onclick event handler and start debug
4. click the button

Expected Behavior

the filepicker shows up

Actual Behavior

the filepicker shows up, then the app throws System.InvalidOperationException: 'Window Not Found' and crash.

Basic Information

• Version with issue: maui preview7
• Last known good version: maui preview6
• IDE: VIsual Studio 2022 preview 3
• Platform Target Frameworks:
  • iOS:
  • Android:
  • UWP:
• Android Support Library Version:
• Nuget Packages:
• Affected Devices:android

Screenshots

Reproduction Link

https://github.com/Chronostasys/ButtonTest

Workaround

[josephatkuvio]

I am seeing the same issue on Preview 7 on Android, in my case when attempting to open a custom tab via MSAL.NET. I’ve tried with the embedded browser as well, same issue, so it seems to be related to the launching of any new activity, or more specifically, the default MAUI OnResume callbacks. Here is a full stack trace upon crash. It appears that something in the MAUI OnResume handlers could be passing the wrong Window object up the chain?

08-13 16:04:20.222 22816 22816 D AndroidRuntime: Shutting down VM
08-13 16:04:20.223 22816 22816 E AndroidRuntime: FATAL EXCEPTION: main
08-13 16:04:20.223 22816 22816 E AndroidRuntime: android.runtime.JavaProxyThrowable: System.InvalidOperationException: Window Not Found
08-13 16:04:20.223 22816 22816 E AndroidRuntime:    at Microsoft.Maui.ContextExtensions.GetWindow(Context context) in Microsoft.Maui.dll:token 0x60001ad+0x7f
08-13 16:04:20.223 22816 22816 E AndroidRuntime:    at Microsoft.Maui.LifecycleEvents.AppHostBuilderExtensions.<>c.<OnConfigureLifeCycle>b__1_2(Activity activity) in Microsoft.Maui.dll:token 0x6000996+0x0
08-13 16:04:20.223 22816 22816 E AndroidRuntime:    at Microsoft.Maui.MauiApplication.ActivityLifecycleCallbacks.<>c__DisplayClass2_0.<OnActivityResumed>b__0(OnResume del) in Microsoft.Maui.dll:token 0x6000ab6+0x0
08-13 16:04:20.223 22816 22816 E AndroidRuntime:    at Microsoft.Maui.LifecycleEvents.LifecycleEventServiceExtensions.InvokeLifecycleEvents[OnResume](IServiceProvider services, Action`1 action) in Microsoft.Maui.dll:token 0x60004d5+0x1d
08-13 16:04:20.223 22816 22816 E AndroidRuntime:    at Microsoft.Maui.MauiApplication.ActivityLifecycleCallbacks.OnActivityResumed(Activity activity) in Microsoft.Maui.dll:token 0x6000887+0x1b
08-13 16:04:20.223 22816 22816 E AndroidRuntime:    at Android.App.Application.IActivityLifecycleCallbacksInvoker.n_OnActivityResumed_Landroid_app_Activity_(IntPtr jnienv, IntPtr native__this, IntPtr native_activity) in Mono.Android.dll:token 0x602506c+0xf
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at crc6488302ad6e9e4df1a.MauiApplication_ActivityLifecycleCallbacks.n_onActivityResumed(Native Method)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at crc6488302ad6e9e4df1a.MauiApplication_ActivityLifecycleCallbacks.onActivityResumed(MauiApplication_ActivityLifecycleCallbacks.java:74)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.Application.dispatchActivityResumed(Application.java:436)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.Activity.dispatchActivityResumed(Activity.java:1379)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.Activity.onResume(Activity.java:1905)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1456)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.Activity.performResume(Activity.java:8135)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.ActivityThread.performResumeActivity(ActivityThread.java:4434)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:4476)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.servertransaction.ResumeActivityItem.execute(ResumeActivityItem.java:52)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:176)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.os.Handler.dispatchMessage(Handler.java:106)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.os.Looper.loop(Looper.java:223)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at android.app.ActivityThread.main(ActivityThread.java:7656)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at java.lang.reflect.Method.invoke(Native Method)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
08-13 16:04:20.223 22816 22816 E AndroidRuntime:        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)

At the moment the new activity is created, the following log code added to OnResume:

Android.Util.Log.Info("", "Activity is " + activity);
Android.Util.Log.Info("", "Window is " + activity.Window);
Android.Util.Log.Info("", "Context is " + activity.GetWindow());

returns this:

08-15 13:54:11.991  4878  4878 I: Activity is crc647e7a282969979595.MainActivity@d9db2e9
08-15 13:54:11.998  4878  4878 I: Window is com.android.internal.policy.PhoneWindow@777de97
08-15 13:54:11.998  4878  4878 I: Context is Microsoft.Maui.Controls.Window

I do see new PR activity around CreateWindow in #2035 by @mattleibow, but it didn’t make it into Preview 7, and seems to revolve around more of an app launch timing issue than anything.

[RNubla]

This bug still persist on preview 9. Is there a temporary workaround atm? Thank you