Fatal Exception: java.lang.NullPointerException in release build

Question

I am facing a weird issue in the release build of the app. Here's my exception

Fatal Exception: java.lang.NullPointerException`
throw with null exception
in.hopq.hopq.authentication.models.AppUpdateSourceDO$AppUpdate.getMinAllowedVersion (AppUpdateSourceDO.java:3)
in.hopq.hopq.authentication.activities.SplashActivity$onCreate$1.onChanged (SplashActivity.java:48)
in.hopq.hopq.authentication.activities.SplashActivity$onCreate$1.onChanged (SplashActivity.java:31)

Pojo File

data class AppUpdateSourceDO(
    @SerializedName("app_update")
    val appUpdate: AppUpdate,
    @SerializedName("message")
    val message: String,
    @SerializedName("success")
    val success: Boolean
) {
data class AppUpdate(
        @SerializedName("excluded_versions")
        val excludedVersions: List<ExcludedVersion>,
        @SerializedName("min_allowed_version")
        val minAllowedVersion: Int,
        @SerializedName("min_allowed_version_ios")
        val minAllowedVersionIos: String,
        @SerializedName("recommended_version")
        val recommendedVersion: Int?
) {
    data class ExcludedVersion(
            @SerializedName("version")
            val version: String
    )
}
}

Here's my proguard file

##OKHTTP3
-keepattributes Signature
-keepattributes *Annotation*
-keep class okhttp3.** { *; }
-keep interface okhttp3.** { *; }
-dontwarn okhttp3.**
-dontnote okhttp3.**
-dontwarn okio.**
-dontwarn retrofit2.Platform$Java8
# Gson uses generic type information stored in a class file when working with fields. Proguard
# removes such information by default, so configure it to keep all of it.
-keepattributes Signature
# For using GSON @Expose annotation
-keepattributes *Annotation*

Answer 1

Finally solved this issue. This is because of the new R8 code obfuscation. Simply disable it from your project by adding this to the gradle.properties file

android.enableR8=false

Additionally you add this to your proguard rules file.

# Prevent R8 from leaving Data object members always null
-keepclassmembers,allowobfuscation class * {
  @com.google.gson.annotations.SerializedName <fields>;
}

However adding this to the proguard didn't really worked out.