> For the complete documentation index, see [llms.txt](https://docs.tryterra.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tryterra.co/faq/help-topics/data-api-sdk/mobile-sdk-setup-permissions-and-crashes/android-release-proguard-r8-keep-rules.md).

# Why does the Flutter SDK fail in release but work in debug?

Code that works in debug but fails in Android release builds means **R8 minification (disabled in debug) is stripping or renaming SDK classes**. Add app-level ProGuard/R8 keep rules for the relevant Terra package and reference your `proguard-rules.pro` in the release `buildType`:

* Standard SDK: `-keep class co.tryterra.** { *; }`
* Real-time SDK: `-keep class co.tryterra.terrartandroid.** { *; }`

Gson 'abstract class can't be instantiated' crashes with obfuscated class names occur because Gson instantiates Terra model classes via reflection. Add the keep rule plus `-keepattributes Signature` and `Annotation`.

If you still see obfuscated names, your `proguard-rules.pro` is not being picked up:

* Confirm the release `buildType` references it.
* With Expo/EAS, run prebuild so `android/app/proguard-rules.pro` is applied.

If you use the direct Samsung Health integration, also keep Samsung's classes: `-keep class com.samsung.android.** { *; }`. Alternatively, disable minification for the release build. See the [Android setup docs](https://docs.tryterra.co/health-and-fitness-api/mobile-only-sources/android-kotlin) for more.