Is this a bug report?

Yes

Have you read the Contributing Guidelines?

Yes

Environment

1. react-native -v: react-native-cli: 2.0.1 react-native: 0.48.1
2. node -v: v7.5.0
3. npm -v: 5.3.0

• Target Platform: Android

• Development Operating System: macOS

• Build tools:

Steps to Reproduce

1. Received a push notification
2. Starting a Service that extends HeadlessJsTaskService.java
3. App throws exception com.facebook.react.bridge.AssertionException: Expected to run on UI thread!

Expected Behavior

I expect no UI thread requirement for a background service (same as Android native SDK)

Actual Behavior

App throws an exception