Crash in Google Mobile Ads SDK 24.3.0 – ConcurrentModificationException in zzfmf.zze

[Bhavesh Solanki]

Hi Team,

We’re seeing a crash in production related to the Google Mobile Ads SDK version 24.3.0.

Fatal Exception: java.util.ConcurrentModificationException
    at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:1111)
    at java.util.ArrayList$Itr.next(ArrayList.java:1064)
    at java.util.Collections$UnmodifiableCollection$1.next(Collections.java:1123)
    at com.google.android.gms.internal.ads.zzfmf.zze(play-services-ads@@24.3.0:3)
    at com.google.android.gms.internal.ads.zzfls.run(play-services-ads@@24.3.0:3)
    at java.lang.Thread.run(Thread.java:1012)

 Context:

• SDK Version: 24.3.0

• Occurring during ad request/render.

• Appears to be a threading issue in internal SDK list iteration

We would appreciate any guidance on:

• Whether this is a known issue

• If a fix is planned or already available in an upcoming release

• Any recommended mitigation until then

[Bhavesh Solanki]

Hi Team,

We’re seeing a crash in production related to the Google Mobile Ads SDK version 24.3.0.

Obfuscated SDK Logs:

Fatal Exception: java.util.ConcurrentModificationException at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:1111) at java.util.ArrayList$Itr.next(ArrayList.java:1064) at java.util.Collections$UnmodifiableCollection$1.next(Collections.java:1123) at com.google.android.gms.internal.ads.zzfmf.zze(play-services-ads@@24.3.0:3) at com.google.android.gms.internal.ads.zzfls.run(play-services-ads@@24.3.0:3) at java.lang.Thread.run(Thread.java:1012)

Context:

• SDK Version: 24.3.0

• Occurring during ad request/render (we suspect it may be triggered on the rendering thread)

• Appears to be a threading issue in internal SDK list iteration

We would appreciate any guidance on:

• Whether this is a known issue

• If a fix is planned or already available in an upcoming release

• Any recommended mitigation until then

Thanks in advance for your help.

[Mobile Ads SDK Forum Advisor]

Hi,

Thank you for contacting the Mobile Ads SDK Support team.

Could you please confirm if the reported issue is replicating in our Google Sample Application? If yes, kindly share the Sample project reproducing the issue.

It would be helpful for our investigation if you could also share the full stack trace and mention if the issue is occurring on any specific devices.

Meanwhile, I will raise this issue with the wider team and will notify you once I receive any updates. Meanwhile, your patience is important. 

If the file(s) you are looking to share are less than 25mb in total you can attach them to this case on your next reply. If you are having trouble attaching your file to this case or if your file(s) are larger than 25mb. Kindly follow using the steps below:

1. Navigate to https://docs.google.com/forms/d/e/1FAIpQLSfkAiXMeYP-fw1W3Z-tT9uwmATEKO5X6S-th0gR2ezdKaaqfg/viewform?usp=pp_url&entry.400550049=Mobile+Ads+SDK&entry.460850823=500Ht00001rgokAIAQ&entry.80707362=00316607

2. Fill out all fields, and attach your file(s).

3. Please reply back on this thread when you have uploaded your file(s). Please do not share this link.

Thanks,
 

Mobile Ads SDK Team

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How was our support today?

               
[2025-07-01 12:45:05Z GMT] This message is in relation to case "ref:!00D1U01174p.!500Ht01rgokA:ref" (ADR-00316607)

[Bhavesh Solanki]

Hi,

I’ve shared the additional crash logs and device information via the Google form.

The crash appears to be straightforward, and identifying the root cause within the SDK should be manageable.

For further context, please refer to the related discussions on the Google Developer Forum:

• Post-1
• Post-2

Given the clarity of the issue, I believe creating and sharing a sample project is not necessary — the logs and forum references should be sufficient for the technical team to analyze and resolve it.

Kindly share this feedback with the tech team at the earliest so the fix can be considered for the next release.

Let me know if any additional information is needed.

Thanks,

Bhavesh

[Mobile Ads SDK Forum Advisor]

Hi Bhavesh,

Thank you for providing the requested information.

Our team is actively engaged in resolving this issue and this will be fixed in v24.5.0 which the target release date is mid-July. 

Thanks,
 

Mobile Ads SDK Team

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How was our support today?

               

[2025-07-10 07:11:50Z GMT] This message is in relation to case "ref:!00D1U01174p.!500Ht01rgokA:ref" (ADR-00316607)