---
title: "Retracing R8 obfuscated stack traces"
canonical_url: "https://www.nutrient.io/guides/android/troubleshooting/miscellaneous/r8-retracing/"
md_url: "https://www.nutrient.io/guides/android/troubleshooting/miscellaneous/r8-retracing.md"
last_updated: "2026-06-09T10:38:40.793Z"
description: "Solutions for common issues and errors in Nutrient Android SDK with debugging tips and workarounds."
---

This guide is for retracing Java stack traces that have been obfuscated with R8 and our ProGuard configuration. These traces often look something like this:

```

java.lang.RuntimeException
PreviewV3Activity
java.nio.charset.MalformedInputException: Input length = 1
Oct 3rd 2023, 09:53:55 UTC

STACKTRACE

java.lang.RuntimeException: java.nio.charset.MalformedInputException: Input length = 1
        at com.pspdfkit.internal.cu.c(cu:29)
        at com.pspdfkit.internal.p1.v(p1:1)
        at com.pspdfkit.internal.b1.a(b1:419)
        at com.pspdfkit.internal.s1.a(s1:120)
        at com.pspdfkit.internal.u1.a(u1:364)
        at com.pspdfkit.internal.u1.getAnnotations(u1:75)
        at com.pspdfkit.internal.u1.b(u1:61)...

Caused by: java.nio.charset.MalformedInputException: Input length = 1
        at java.nio.charset.CoderResult.throwException(CoderResult.java:281)
        at com.pspdfkit.internal.cu.c(cu:22)
        at com.pspdfkit.internal.p1.v(p1:1)...

THREADS

Thread 2 - main
        at android.content.res.AssetManager.getResourceValue(AssetManager.java:504)
        at android.content.res.ResourcesImpl.getValue(ResourcesImpl.java:233)
        at android.content.res.Resources.getBoolean(Resources.java:1089)
        at com.android.internal.policy.DecorView.calculateNavigationBarColor(DecorView.java:1323)
        at com.android.internal.policy.DecorView.updateColorViews(DecorView.java:1168)...

Thread xxx - etc
Thread etc
etc

```

For NDK stack traces from our core C++ library, see the [NDK crash reports](https://www.nutrient.io/guides/android/troubleshooting/bug-reporting.md#ndk-crash-reports) guide.

Our ProGuard configuration obfuscates the code in our `internal` package, so if it crashes in there, it’s hard for us to determine the source.

We share the ProGuard mapping file for a certain release on request. Contact us at [support@nutrient.io](mailto:support@nutrient.io) to get it. You can also open a support ticket with the crash trace and the version number and we can deobfuscate it. If you want to do it yourself, follow the steps below.

1. Run the `proguardgui.sh` app shipped with the Android SDK. On Mac, it’s usually here:

   `~/Library/Android/sdk/tools/proguard/bin/proguardgui.sh`

2. Click the **ReTrace** button.

3. Paste the obfuscated trace in the **Obfuscated stack trace** box.

4. Add the mapping file using the **Browse...** button or by adding the path directly in the box.

5. Click **ReTrace!**

6. You’ll now see the obfuscated functions, and you can share this with our Support team.

The image below shows what the ProGuard window looks like.
---

## Related pages

- [Layout Problems](/guides/android/troubleshooting/layout-problems.md)
- [Make sure to replace :app with the name of your Android app or library module.](/guides/android/troubleshooting/androidx-migration.md)
- [Assuming the crash report came from an arm64 device.](/guides/android/troubleshooting/bug-reporting.md)
- [Path Traversal Vulnerability](/guides/android/announcements/path-traversal-vulnerability.md)