[Bug]: java.util.ConcurrentModificationException on Android

[rarenatoe]

Required Reading

• Confirmed

Plugin Version

4.18.7

Mobile operating-system(s)

• iOS
• Android

Device Manufacturer(s) and Model(s)

SM-S908U1, SM-S918U, SM-S928U1, moto g - 2025

Device operating-systems(s)

Android 14, Android 15

React Native / Expo version

0.77, Expo 52

What happened?

I know there was a fix for this bug at 4.18.7, but my production build is currently giving this error regardless.

Roughly 5 out of 40 users are experiencing this issue.

Plugin Code and/or Config

import { Platform } from 'react-native'
import BackgroundGeolocation, { Config } from 'react-native-background-geolocation'

const STOP_TIMEOUT = 10
const DISTANCE_METERS = 150
const INTERVAL_MILLISECONDS = 15000

const geolocationSettings: Config = {
  desiredAccuracy:
    Platform.OS === 'ios'
      ? BackgroundGeolocation.DESIRED_ACCURACY_NAVIGATION
      : BackgroundGeolocation.DESIRED_ACCURACY_HIGH,
  // Android only
  backgroundPermissionRationale: {
    title: `Allow {applicationName} to access this device's location in the background?`,
    message:
      'Swoop needs to use background location tracking to display truck locations on the map within the app. Swoop will only track your location when you are logged in to the app and on duty.',
  },
  distanceFilter: DISTANCE_METERS,
  disableElasticity: true,
  enableHeadless: true,
  fastestLocationUpdateInterval: INTERVAL_MILLISECONDS,
  foregroundService: true,
  notification: {
    title: 'Swoop',
    text: 'Tracking your location',
    smallIcon: 'ic_notification',
  },
  allowIdenticalLocations: true,

  // This will keep location services always on (this used to be true)
  disableStopDetection: false,
  // Stop on app terminate
  stopOnTerminate: false,
  // Restart tracking on phone restart
  startOnBoot: false,
  maxRecordsToPersist: 1,

  // This is the motion permission which will help battery life (used to be true)
  // We're disabling this for Android as it requires the ACTIVITY_RECOGNITION permission,
  // which has been removed due to conflicts with Google Play Store policies.
  disableMotionActivityUpdates: Platform.OS !== 'ios',

  /*
   * Without reset: true, the plugin will cache settings and ignore changes to them
   */
  reset: true,

  locationAuthorizationRequest: 'Always',
  // Activity Recognition
  stopTimeout: STOP_TIMEOUT,
  // Set true to sync multiple stored locations to server in a single HTTP request.
  batchSync: false,
  //  Set true to sync each location to server as it arrives.
  autoSync: true,

  url: '',
  httpRootProperty: '',
  locationTemplate: '',
  headers: {},
}

Relevant log output

Rollbar is reporting this as the error log:

.util.ConcurrentModificationException: <Unknown message> at 
com.swoopmobile.MainApplication.handleUncaughtException(Unknown Source:54) at 
com.swoopmobile.MainApplication.onCreate$lambda$0(Unknown Source:43) at 
com.swoopmobile.MainApplication.$r8$lambda$s6PvkmEnFg9JA6AEnrpWru6NMZo(Unknown Source:0) at 
n9.MainApplication$$ExternalSyntheticLambda0.uncaughtException(Unknown Source:2) at 
com.transistorsoft.locationmanager.adapter.BackgroundGeolocation$w0.uncaughtException(Unknown Source:98) at 
java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1071) at 
java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1066) at 
java.lang.Thread.dispatchUncaughtException(Thread.java:2306)

[rarenatoe]

Update: I am having 16 affected devices in 176 installed devices, which is 8% of the population.

[christocracy]

Nobody else it reporting a ConcurrentModificationException currently so it could be related to something happening specific to your own app.

There's typically more evidence from ConcurrentModificationException but there's only 1 line, which isn't much to go on:

com.transistorsoft.locationmanager.adapter.BackgroundGeolocation$w0

Do you have custom modifications within MainApplication.java (or MainApplication.kt)?

The published demo app on Play Store hasn't seen an ANR or crash in 60 days.

[christocracy]

The plugin does have a global "uncaught exception handler" that catches all uncaught exception of all code in your app (so it can log them to its error log database). That could be why com.transistorsoft.locationmanager.adapter.BackgroundGeolocation$w0.uncaughtException appears in your stacktrace.

[rarenatoe]

this is my MainApplication.kt

package com.swoopmobile
import android.content.res.Configuration
import expo.modules.ApplicationLifecycleDispatcher
import expo.modules.ReactNativeHostWrapper

import android.app.Application
import com.facebook.react.PackageList
import com.facebook.react.ReactApplication
import com.facebook.react.ReactHost
import com.facebook.react.ReactNativeHost
import com.facebook.react.ReactPackage
import com.facebook.react.defaults.DefaultNewArchitectureEntryPoint.load
import com.facebook.react.defaults.DefaultReactHost.getDefaultReactHost
import com.facebook.react.defaults.DefaultReactNativeHost
import com.facebook.react.soloader.OpenSourceMergedSoMapping
import com.facebook.soloader.SoLoader
import com.rollbar.RollbarReactNative

class MainApplication : Application(), ReactApplication {

    override val reactNativeHost: ReactNativeHost = ReactNativeHostWrapper(this, object : DefaultReactNativeHost(this) {
        override fun getPackages(): List<ReactPackage> = PackageList(this).packages.apply {
            // Packages that cannot be autolinked yet can be added manually here:
             add(CustomPackage())
        }

        override fun getJSMainModuleName(): String = "index"

        override fun getUseDeveloperSupport(): Boolean = BuildConfig.DEBUG

        override val isNewArchEnabled: Boolean = BuildConfig.IS_NEW_ARCHITECTURE_ENABLED
        override val isHermesEnabled: Boolean = BuildConfig.IS_HERMES_ENABLED
    })

    override val reactHost: ReactHost
        get() = ReactNativeHostWrapper.createReactHost(applicationContext, reactNativeHost)

    override fun onCreate() {
        super.onCreate()
        SoLoader.init(this, OpenSourceMergedSoMapping)
        RollbarReactNative.init(this, BuildConfig.ROLLBAR_TOKEN, BuildConfig.ENVIRONMENT)
        Thread.setDefaultUncaughtExceptionHandler { thread, e ->
            handleUncaughtException(thread, e)
        }
        if (BuildConfig.IS_NEW_ARCHITECTURE_ENABLED) {
            // If you opted-in for the New Architecture, we load the native entry point for this app.
            load()
        }
        ApplicationLifecycleDispatcher.onApplicationCreate(this)
    }

    fun handleUncaughtException(thread: Thread, e: Throwable) {
        // CALL Rollbar Notifier here to send an error or critical...
        RollbarReactNative.error(e.fillInStackTrace())
    }

    override fun onConfigurationChanged(newConfig: Configuration) {
        super.onConfigurationChanged(newConfig)
        ApplicationLifecycleDispatcher.onConfigurationChanged(this, newConfig)
    }
}

[github-actions]

This issue is stale because it has been open for 30 days with no activity.