Tencent/QMUI_Android · critical · IllegalAccessError

the QMUISwipeBackActivityManager is not initialized; please

Error message

the QMUISwipeBackActivityManager is not initialized; please call QMUISwipeBackActivityManager.init(Application) in your application.

What it means

QMUISwipeBackActivityManager is a singleton that must be registered as an Application.ActivityLifecycleCallbacks via init(Application). getInstance() is @MainThread and throws IllegalAccessError when sInstance is null, i.e. when the swipe-back manager was never initialized, because activity tracking (needed for swipe-back gestures) cannot work without it.

Source

Thrown at arch/src/main/java/com/qmuiteam/qmui/arch/QMUISwipeBackActivityManager.java:38

import android.app.Application;
import android.os.Bundle;
import androidx.annotation.MainThread;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import java.util.Stack;


public class QMUISwipeBackActivityManager implements Application.ActivityLifecycleCallbacks {
    private static QMUISwipeBackActivityManager sInstance;
    private Stack<Activity> mActivityStack = new Stack<>();
    private Activity mCurrentActivity = null;


    @MainThread
    public static QMUISwipeBackActivityManager getInstance() {
        if (sInstance == null) {
            throw new IllegalAccessError("the QMUISwipeBackActivityManager is not initialized; " +
                    "please call QMUISwipeBackActivityManager.init(Application) in your application.");
        }
        return sInstance;
    }

    private QMUISwipeBackActivityManager() {
    }

    public static void init(@NonNull Application application) {
        if (sInstance == null) {
            sInstance = new QMUISwipeBackActivityManager();
            application.registerActivityLifecycleCallbacks(sInstance);
        }
    }

    @Override
    public void onActivityCreated(@NonNull Activity activity, Bundle savedInstanceState) {
        if(mCurrentActivity == null){

View on GitHub (pinned to 026e7d4866)

Solutions

Call QMUISwipeBackActivityManager.init(this) inside your Application.onCreate().
Verify AndroidManifest <application android:name=".MyApp"> points to the Application class that performs the init.
Check init() is not gated behind a flag/build variant that skips it (e.g. only in debug).
For non-UI code paths, avoid touching getInstance() before Application.onCreate completes.

Example fix

// before
public class MyApp extends Application {
    @Override public void onCreate() {
        super.onCreate();
    }
}
// after
@Override public void onCreate() {
    super.onCreate();
    QMUISwipeBackActivityManager.init(this);
}

Defensive patterns

Strategy: validation

Validate before calling

if (QMUISwipeBackActivityManager.getInstanceOrNull() == null) { // or guard in Application
    QMUISwipeBackActivityManager.init(application);
}

Try / catch

try {
    QMUISwipeBackActivityManager.getInstance().someOp();
} catch (IllegalAccessError e) {
    QMUISwipeBackActivityManager.init(application);
    // retry once
}

Prevention

Call QMUISwipeBackActivityManager.init(this) first in Application.onCreate()
Verify AndroidManifest android:name references your Application class
Don't call swipe-back APIs from tests/ContentProviders before app init

When it happens

Trigger: Calling QMUISwipeBackActivityManager.getInstance() (or using QMUISwipeBackActivity / swipe-back features) before/without invoking QMUISwipeBackActivityManager.init(application) in your Application subclass; also occurs when the custom Application class is not registered in AndroidManifest.

Common situations: Forgetting init() when adding swipe-back to a project, AndroidManifest android:name not pointing at the Application class that performs init, or code paths (unit tests, content providers) running before Application.onCreate.

Understand the failure class

Background: "X is required", "must be set", "cannot be empty": the missing-required-config error family, from Vertex AI project/location to WeChat keys — this error's family across 18 libraries.

Related errors

AI-assisted analysis of Tencent/QMUI_Android@026e7d4866 (2026-09-06). Data as JSON: /api/errors/f8725c9e9ec49291. Report an issue: GitHub.