NullPointerException: Attempt to invoke virtual method 'int java.util.AbstractCollection.size()' on a null object reference

[Illia Achour]

Hi AdMob team,

We’re seeing a recurrent crash inside the Google Mobile Ads SDK (com.google.android.gms:play-services-ads:24.8.0) on ChromeOS devices (AMD Stoney Ridge Chromebooks). None of our app code is involved.

Android 11

SDK version: 24.8.0

Device: Google Cros AMD Stoney Ridge Chromebook

Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'int java.util.AbstractCollection.size()' on a null object reference
   at com.google.android.gms.internal.ads.zzgtb.<init>(com.google.android.gms:play-services-ads@@24.8.0:1)
   at com.google.android.gms.internal.ads.zzgtd.<clinit>(com.google.android.gms:play-services-ads@@24.8.0:1)
   at com.google.android.gms.internal.ads.zzgtd.zzt(com.google.android.gms:play-services-ads@@24.8.0:2)
   at com.google.android.gms.internal.ads.zzgtd.zzq(com.google.android.gms:play-services-ads@@24.8.0:6)
   at com.google.android.gms.internal.ads.zzgtd.zzp(zzgtd.java:1)
   at com.google.android.gms.internal.ads.zzgym.zzn(com.google.android.gms:play-services-ads@@24.8.0:1)
   at com.google.android.gms.internal.ads.zzdzp.zzl(zzdzp.java:47)
   at com.google.android.gms.internal.ads.zzdze.run(zzdze.java:1)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
   at java.lang.Thread.run(Thread.java:923)

We unfortunately cannot reproduce this crash on any of our test devices or emulators, and we don’t know the exact conditions that trigger it. Since it happens entirely inside SDK internals, we’re hoping you can analyze the possible code paths that lead to a null collection being passed.