Troubleshooting Guide

Fail to Pair Monaca Debugger

Several reasons can be considered when Monaca Debugger fails to pair with the host PC such as:

Monaca Debugger can see the host PC but fail to pair

this is most likely a firewall problem in the host PC. The host PC needs to accept TCP connection from the debugger. Port 8001 will be used, and you can change the server port in Preferences dialog. Please change the port or configure your firewall settings to try agian.

Monaca Debugger does not detect the host PC

please check and see if your device and the host PC are connected to the same network. If they are connected to the same network but Monaca Debugger still can’t detect the host PC, please do a manual pairing.

  1. From Monaca Debugger, click on the toggle menu on the top-left corner and select Local Computers.

  2. Click Pair the New Computer button.

  3. Input the IP address of the host PC and port number. Then, click Pair button.

  4. Once the pairing is successfully completed, the host PC should appear under Paired computers as shown below:

Pairing fails on Android 9+.

When using a custom build debugger on Android 9 or later, you need to add the andorid namespace to the widget tag in config.xml and add usesCleartextTraffic.

Create the custom build debugger after adding the following settings to config.xml.

If you are using Android custom build debugger v9.0.1 or later, the following settings are not required.
<widget xmlns:android="">

<platform name="android">
  <edit-config file="AndroidManifest.xml" target="/manifest/application" mode="merge">
    <application android:usesCleartextTraffic="true" />
Some Wi-Fi access points (usually that is available for public access) don’t allow the connected clients to communicate each other. In this case, please try pairing on another local network.

IP Address and Port Number

IP address and port number are needed to establish the communication path between Monaca Debugger and the host PC. IP address represents the host PC and port number (set to 8001 by default) represents Monaca local development tool (such as Monaca CLI, Localkit or Monaca for Visual Studio). Please note that the communication can’t be established if the port number you use is not opened or is already used.

In case, you are using more than one of Monaca local development tools at the same time on the same host PC, you are required to use different port for each tool. Otherwise, the pair will fail.
OS Mac Windows
IP Address Find IP address:
  1. Open Terminal window.
  2. Type ifconfig.
Find IP address:
  1. Open Command Prompt window.
  2. Type ipconfig.
Port Number Check if a port number is available:
  1. Open Terminal window.
  2. Type lsof -i :PORT_NUMBER.
Check if a port number is available:
  1. Open Command Prompt window.
  2. Type netstat.

Inspector Isn’t Loaded

If the inspector does not open, please try the following actions:

  • verify if you have done all necessary setups described here.
  • verify that you are running the application on the debugger.
  • try plug off & in to see if the computer can find the device.
  • check if the device and the host PC are connected via USB cable.
  • check if you use the right Monaca Debugger.
  • kill all adb processes if multiple of them are running.
  • kill all iosWebKitDebugProxy processes if multiple of them are running.
  • restart the host PC.

See Also: