🐛 If the BLE device disconnects actively, an error will be reported in android

[i7soft]

Prerequisites

• I checked the documentation and FAQ without finding a solution
• I checked to make sure that this issue has not already been filed

Expected Behavior

no error

Current Behavior

app exit

Library version

3.5.0

Device

Android

Environment info

System:
  OS: macOS 26.1
  CPU: (10) arm64 Apple M1 Pro
  Memory: 132.69 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 23.11.0
    path: /opt/homebrew/bin/node
  Yarn:
    version: 3.6.4
    path: /opt/homebrew/bin/yarn
  npm:
    version: 10.9.2
    path: /opt/homebrew/bin/npm
  Watchman:
    version: 2025.05.19.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /opt/homebrew/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 25.0
      - iOS 26.0
      - macOS 26.0
      - tvOS 26.0
      - visionOS 26.0
      - watchOS 26.0
  Android SDK: Not Found
IDEs:
  Android Studio: 2025.1 AI-251.26094.121.2513.14007798
  Xcode:
    version: 26.0/17A324
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.9
    path: /usr/bin/javac
  Ruby:
    version: 3.4.4
    path: /opt/homebrew/opt/ruby/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.0.2
    wanted: ^20.0.2
  react:
    installed: 19.1.1
    wanted: 19.1.1
  react-native:
    installed: 0.82.1
    wanted: ^0.82.1
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: Not found
  newArchEnabled: false

Steps to reproduce

1. BLE device conect
   2.close the BLE device power

Formatted code sample or link to a repository

I have fixed this bug:

node_modules/react-native-ble-plx/android/src/main/java/com/bleplx/BlePlxModule.java

line 797: safePromise.reject(null, errorConverter.toJs(error));

first param "null" is not allow

so,change to :

safePromise.reject(error.errorCode.name(), errorConverter.toJs(error));

Relevant log output

io.reactivex.exceptions.CompositeException: 2 exceptions occurred. 
                                                                                                    	at io.reactivex.internal.subscribers.LambdaSubscriber.onError(LambdaSubscriber.java:82)
                                                                                                    	at io.reactivex.internal.operators.flowable.FlowableDoOnEach$DoOnEachSubscriber.onError(FlowableDoOnEach.java:111)
                                                                                                    	at io.reactivex.internal.operators.flowable.FlowableDoOnLifecycle$SubscriptionLambdaSubscriber.onError(FlowableDoOnLifecycle.java:85)
                                                                                                    	at io.reactivex.internal.operators.flowable.FlowableObserveOn$BaseObserveOnSubscriber.checkTerminated(FlowableObserveOn.java:209)
                                                                                                    	at io.reactivex.internal.operators.flowable.FlowableObserveOn$ObserveOnSubscriber.runAsync(FlowableObserveOn.java:399)
                                                                                                    	at io.reactivex.internal.operators.flowable.FlowableObserveOn$BaseObserveOnSubscriber.run(FlowableObserveOn.java:176)
                                                                                                    	at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:66)
                                                                                                    	at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:57)
                                                                                                    	at java.util.concurrent.FutureTask.run(FutureTask.java:264)
                                                                                                    	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:307)
                                                                                                    	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1137)
                                                                                                    	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:637)
                                                                                                    	at java.lang.Thread.run(Thread.java:1023)
                                                                                                      ComposedException 1 :
                                                                                                    	com.polidea.rxandroidble2.exceptions.BleDisconnectedException: Disconnected from MAC='XX:XX:XX:XX:XX:XX' with status 0 (GATT_SUCCESS)
                                                                                                    		at com.polidea.rxandroidble2.internal.connection.RxBleGattCallback$2.onConnectionStateChange(RxBleGattCallback.java:81)
                                                                                                    		at android.bluetooth.BluetoothGatt$1$4.run(BluetoothGatt.java:299)
                                                                                                    		at android.bluetooth.BluetoothGatt.runOrQueueCallback(BluetoothGatt.java:864)
                                                                                                    		at android.bluetooth.BluetoothGatt.-$$Nest$mrunOrQueueCallback(Unknown Source:0)
                                                                                                    		at android.bluetooth.BluetoothGatt$1.onClientConnectionState(BluetoothGatt.java:294)
                                                                                                    		at android.bluetooth.IBluetoothGattCallback$Stub.onTransact(IBluetoothGattCallback.java:128)
                                                                                                    		at android.os.Binder.execTransactInternal(Binder.java:1286)
                                                                                                    		at android.os.Binder.execTransact(Binder.java:1244)
                                                                                                    	Caused by: java.lang.NullPointerException: Parameter specified as non-null is null: method com.facebook.react.bridge.PromiseImpl.reject, parameter code
                                                                                                    		at com.facebook.react.bridge.PromiseImpl.reject(Unknown Source:2)
                                                                                                    		at com.bleplx.utils.SafePromise.reject(SafePromise.java:25)
                                                                                                    		at com.bleplx.BlePlxModule$41.onError(BlePlxModule.java:797)
                                                                                                    		at com.bleplx.adapter.utils.SafeExecutor.error(SafeExecutor.java:30)
                                                                                                    		at com.bleplx.adapter.BleModule.lambda$safeMonitorCharacteristicForDevice$45(BleModule.java:1485)
                                                                                                    		at com.bleplx.adapter.BleModule.$r8$lambda$JVuqIGnSfaxzZFLoyHm91xQUhdI(Unknown Source:0)
                                                                                                    		at com.bleplx.adapter.BleModule$$ExternalSyntheticLambda3.accept(D8$$SyntheticClass:0)
                                                                                                    		at io.reactivex.internal.subscribers.LambdaSubscriber.onError(LambdaSubscriber.java:79)
                                                                                                    		at io.reactivex.internal.operators.flowable.FlowableDoOnEach$DoOnEachSubscriber.onError(FlowableDoOnEach.java:111)
                                                                                                    		at io.reactivex.internal.operators.flowable.FlowableDoOnLifecycle$SubscriptionLambdaSubscriber.onError(FlowableDoOnLifecycle.java:85)
                                                                                                    		at io.reactivex.internal.operators.flowable.FlowableObserveOn$BaseObserveOnSubscriber.checkTerminated(FlowableObserveOn.java:209)
                                                                                                    		at io.reactivex.internal.operators.flowable.FlowableObserveOn$ObserveOnSubscriber.runAsync(FlowableObserveOn.java:399)
                                                                                                    		at io.reactivex.internal.operators.flowable.FlowableObserveOn$BaseObserveOnSubscriber.run(FlowableObserveOn.java:176)
                                                                                                    		at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:66)
                                                                                                    		at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:57)
                                                                                                    		at java.util.concurrent.FutureTask.run(FutureTask.java:264)
                                                                                                    		at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:307)
2025-12-04 14:30:47.551 23378-23645 AndroidRuntime          com.zgcqnx.pe                        E  		at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1137)
                                                                                                    		at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:637)
                                                                                                    		at java.lang.Thread.run(Thread.java:1023)
                                                                                                      ComposedException 2 :
                                                                                                    	java.lang.NullPointerException: Parameter specified as non-null is null: method com.facebook.react.bridge.PromiseImpl.reject, parameter code
                                                                                                    		at com.facebook.react.bridge.PromiseImpl.reject(Unknown Source:2)
                                                                                                    		at com.bleplx.utils.SafePromise.reject(SafePromise.java:25)
                                                                                                    		at com.bleplx.BlePlxModule$41.onError(BlePlxModule.java:797)
                                                                                                    		at com.bleplx.adapter.utils.SafeExecutor.error(SafeExecutor.java:30)
                                                                                                    		at com.bleplx.adapter.BleModule.lambda$safeMonitorCharacteristicForDevice$45(BleModule.java:1485)
                                                                                                    		at com.bleplx.adapter.BleModule.$r8$lambda$JVuqIGnSfaxzZFLoyHm91xQUhdI(Unknown Source:0)
                                                                                                    		at com.bleplx.adapter.BleModule$$ExternalSyntheticLambda3.accept(D8$$SyntheticClass:0)
                                                                                                    		at io.reactivex.internal.subscribers.LambdaSubscriber.onError(LambdaSubscriber.java:79)
                                                                                                    		at io.reactivex.internal.operators.flowable.FlowableDoOnEach$DoOnEachSubscriber.onError(FlowableDoOnEach.java:111)
                                                                                                    		at io.reactivex.internal.operators.flowable.FlowableDoOnLifecycle$SubscriptionLambdaSubscriber.onError(FlowableDoOnLifecycle.java:85)
                                                                                                    		at io.reactivex.internal.operators.flowable.FlowableObserveOn$BaseObserveOnSubscriber.checkTerminated(FlowableObserveOn.java:209)
                                                                                                    		at io.reactivex.internal.operators.flowable.FlowableObserveOn$ObserveOnSubscriber.runAsync(FlowableObserveOn.java:399)
                                                                                                    		at io.reactivex.internal.operators.flowable.FlowableObserveOn$BaseObserveOnSubscriber.run(FlowableObserveOn.java:176)
                                                                                                    		at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:66)
                                                                                                    		at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:57)
                                                                                                    		at java.util.concurrent.FutureTask.run(FutureTask.java:264)
                                                                                                    		at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:307)
                                                                                                    		at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1137)
                                                                                                    		at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:637)
                                                                                                    		at java.lang.Thread.run(Thread.java:1023)

Additional information

No response

[ademhatay]

Same error. My Android app closes when any device is disconnected. with version 3.5.0

[i7soft]

Same error. My Android app closes when any device is disconnected. with version 3.5.0

I have fixed this bug:

node_modules/react-native-ble-plx/android/src/main/java/com/bleplx/BlePlxModule.java

line 797: safePromise.reject(null, errorConverter.toJs(error));

first param "null" is not allow

so,change to :

safePromise.reject(error.errorCode.name(), errorConverter.toJs(error));

[yangwudong]

I got the same error and fixed by changing SafePromise

`diff --git a/node_modules/react-native-ble-plx/android/src/main/java/com/bleplx/utils/SafePromise.java b/node_modules/react-native-ble-plx/android/src/main/java/com/bleplx/utils/SafePromise.java
index 0203473..5e06c2a 100644
--- a/node_modules/react-native-ble-plx/android/src/main/java/com/bleplx/utils/SafePromise.java
+++ b/node_modules/react-native-ble-plx/android/src/main/java/com/bleplx/utils/SafePromise.java
@@ -22,7 +22,7 @@ public class SafePromise {

public void reject(String code, String message) {
if (isFinished.compareAndSet(false, true)) {

•  promise.reject(code, message);
  

•  promise.reject(code != null ? code : "UNKNOWN_ERROR", message);
  

  }
  }

`

[sfourdrinier]

@yangwudong check against my fork and let me know if this is fixed or not there.

https://github.com/sfourdrinier/react-native-ble-plx

[Ruud-BMair]

This looks like the same bug as is discussed in #1303, might be worth checking out.

[bwindsor]

I think this is now fixed in #1329 (released with 3.5.1)

[p-dot-max]

This is resolved by #1329 in 3.5.1. I tested it locally and everything is working as expected now — no app crashes were observed.

I think this PR/issue can be closed.