Null Pointer Exception with Unknown source (Ud.f)

Question

I have an App published in google app store and i get strange log about a crash from an unknown source.

This happens on devices like Xiaomi Redmi Note 5 Pro (whyred), 3840MB RAM, Android 9.

I try to find the same issue reported anywhere but i couldn't.

java.lang.NullPointerException:


    at com.baruchi.simpletime.main.Ud.f (Unknown Source:43)
    at b.j.a.h.k (Unknown Source)
    at b.j.a.v.m (Unknown Source:13)
    at b.j.a.v.w (Unknown Source:77)
    at b.j.a.h.k (Unknown Source:7)
    at b.j.a.v.m (Unknown Source:13)
    at b.j.a.v.w (Unknown Source:77)
    at b.j.a.m.m (Unknown Source:4)
    at b.j.a.k.onSaveInstanceState (Unknown Source:8)
    at androidx.appcompat.app.m.onSaveInstanceState (Unknown Source)
    at com.baruchi.simpletime.main.MainActivity.onSaveInstanceState (Unknown Source)
    at android.app.Activity.performSaveInstanceState (Activity.java:1599)
    at android.app.Instrumentation.callActivityOnSaveInstanceState (Instrumentation.java:1444)
    at android.app.ActivityThread.callActivityOnSaveInstanceState (ActivityThread.java:4872)
    at android.app.ActivityThread.callActivityOnStop (ActivityThread.java:4214)
    at android.app.ActivityThread.handleSleeping (ActivityThread.java:4340)
    at android.app.ActivityThread.access$2400 (ActivityThread.java:200)
    at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1772)
    at android.os.Handler.dispatchMessage (Handler.java:106)
    at android.os.Looper.loop (Looper.java:201)
    at android.app.ActivityThread.main (ActivityThread.java:6810)
    at java.lang.reflect.Method.invoke (Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:547)
    at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:873)

You are getting a crash from unknown source as you must have Proguard enabled on your app. You can check for mappings.txt file to identify which class is renamed to "Ud" by proguard. — NIKHIL AGGARWAL, Apr 01 '20 at 06:15

score 0 · Accepted Answer · answered Apr 01 '20 at 06:28

As NIKHIL AGGARWAL said, the application renamed (obfuscated) classes and methods with Proguard (or R8). You should have mapping.txt to deobfuscate these names.

So, checkout the release branch (that commit after that you released the application). Then generate signed aab or apk. In app\build\outputs\mapping\release you will see resources.txt and mapping.txt files. Save them to another folder. You can manually see, what happens in mapping.txt. Load this file to your analytics system where you see crash logs.

Null Pointer Exception with Unknown source (Ud.f)

1 Answers1