"JNI FatalError called: Unable to load library"

Question

I have a unity project configured to be a dynamic feature module. This installs perfectly fine on-demand. But when I run it, the app crashes with following error:

JNI FatalError called: Unable to load library: /data/app/com.example.app-8fx1RRZrQ34BcwXf8ajjqZ==/lib/arm64/libunity.so [dlopen failed: library "libunity.so" not found]

The target activity of the Unity project includes SplitCompat.install(this);

And it's gradle looks like:

    // GENERATED BY UNITY. REMOVE THIS COMMENT TO PREVENT OVERWRITING WHEN EXPORTING AGAIN

    buildscript {
        repositories {
            mavenCentral()
            google()
            jcenter()
        }

        dependencies {
            classpath 'com.android.tools.build:gradle:3.5.0'
        }
    }

    allprojects {
        repositories {
            mavenCentral()
            google()
            jcenter()
            flatDir {
                dirs 'libs'
            }
        }
    }

    apply plugin: 'com.android.dynamic-feature'

    dependencies {
        implementation fileTree(dir: 'libs', include: ['*.jar'])
    }

    android {
        compileSdkVersion rootProject.compileSdk
        buildToolsVersion rootProject.buildTools

        compileOptions {
            sourceCompatibility JavaVersion.VERSION_1_8
            targetCompatibility JavaVersion.VERSION_1_8
        }

        defaultConfig {
            minSdkVersion rootProject.minSdk
            targetSdkVersion rootProject.targetSdk
            versionCode rootProject.versionCode
            versionName rootProject.versionName

            ndk {
                abiFilters 'armeabi-v7a', 'arm64-v8a'
            }
        }

        lintOptions {
            abortOnError false
        }

        aaptOptions {
            noCompress = ['.unity3d', '.ress', '.resource', '.obb']
        }

        flavorDimensions "default"

        productFlavors {
            staging {
                dimension "default"
            }

            production {
                dimension "default"
            }

            develop {
                dimension "default"
            }
        }

        compileOptions {
            sourceCompatibility 1.8
            targetCompatibility 1.8
        }

        buildTypes {
            debug {
                minifyEnabled false
                useProguard false
                jniDebuggable true
            }
            release {
                minifyEnabled false
                useProguard false
            }
        }

        packagingOptions {
            doNotStrip '*/armeabi-v7a/*.so'
            doNotStrip '*/arm64-v8a/*.so'
    //        doNotStrip '*/x86/*.so'
        }

    }

    dependencies {
        implementation project(':app')
    }

While the gradle of app module has:

    bundle {
        language {
            // Specifies that the app bundle should not support
            // configuration APKs for language resources. These
            // resources are instead packaged with each base and
            // dynamic feature APK.
            enableSplit = false
        }
        density {
            // This property is set to true by default.
            enableSplit = false
        }
        abi {
            // This property is set to true by default.
            enableSplit = true
        }
    }

I even tried disabling the .so compression by setting android.bundle.enableUncompressedNativeLibs = false in gradle.properties file, but the exact error persists.

Internals of the feature module as seen in the aab. The .so libs are present:

How may I resolve this?

Update 1 -

The problem i've described above occurs when the aab is installed from play store for the first time. Note that I am able to successfully install the feature module and the error occurs only when I attempt to run it. However, when I push an incremental update over the same installation, the feature module is somehow able to work flawlessly and is able to find the necessary .so file. I've tried these steps several times on repeat to validate the observation.

Answer 1

Make sure the unity library is loaded using SplitCompat in your dynamic feature modules: https://developer.android.com/guide/app-bundle/playcore#load_native_libs

I'm not sure if this is handled automatically by Unity, but if it is you might want to reach out to them to address this.

Answer 2

I was also seeing "JNI Fatal Error called: Unable to load library .../libunity.so" in log files.

In my case, I noticed that Unity logged an error about not being able to read the bin/Data/settings.xml file. I added those directories and the file to my project's assets and then the libunity library was able to load. So even though you may see a message saying the libunity.so file was not found, the problem is really that the unity library was not able to initialize properly.