[Android]App Crashes randomly with NavigationPageRenderer.UpdateToolbar error

[niraj-bpsoftware]

Description

We have a reoccurring bug in the app over the past month that we are struggling to get to the bottom of, It’s in android only.

This error occurs randomly if you close the app, then open it up again after some time – hours / days. We have not found a reliable we to constantly reproduce this error, but we are getting it regularly, (once to twice a day).
It appears something is going wrong with the bootup process. The problem is very hard to reliably reproduce it appears to occur 1 to 3 seconds after a book. It doesn’t happen in debug mode, we can only trace the problem through the App Centre analytics.

The error is :
NavigationPageRenderer.UpdateToolbar ()
NavigationPageRenderer.OnAttachedToWindow ()
View.n_OnAttachedToWindow (System.IntPtr jnienv, System.IntPtr native__this)
(wrapper dynamic-method) System.Object.42(intptr,intptr)

Steps to Reproduce

1. Login to App.
2. Close the App
3. Open after some time (may be 30 minutes).
   report-2518577414087959999-a4dd2419-076f-4b2d-94e0-6dfe7273d405.txt

Expected Behavior

App shouldn't crash.

Actual Behavior

App crashes randomly on load.

Basic Information

• Version with issue: Xamarin Forms 3.4.0.1008975
• Last known good version: NA
• IDE: 15.8.7
• Platform Target Frameworks:
  • Android: 7.0
  • Android Build: NRD90M
• Android Support Library Version:
• Nuget Packages: ReactiveUi 9.4.1, System.Reactive 4.1.2
• Affected Devices: Android devices

[hartez]

@niraj-bpsoftware Are you using MvvmCross in your application?

[niraj-bpsoftware]

Hi @hartez ,
Thank you for checking this.
we are using MvvmCross.Platform 5.7.0 and MvvmCross.Plauglin.Ble 1.3.0 for Bluetooth functionality.
Thanks.

[filipnavara]

This can be reproduced quite reliably with the "don't keep activities" developer option. In our case we also had to combine it with launching the app with intent after the activity was destroyed (eg. through shortcut or a notification). The crash seems to happen because activity.SupportActionBar == null.