APK Installation Problems

This section covers problems that occur after Gradle successfully builds the APK, but React Native fails while installing it on the Android device.

Problem 1 — InstallException: EOF

Example:

text 
> Task :app:installDebug FAILED

[Device]: Error during Sync: EOF

com.android.ddmlib.InstallException: EOF

Caused by: java.io.EOFException: EOF
at com.android.ddmlib.SyncService.doPushFile(...)

This means the APK was built successfully, but ADB failed while transferring/installing the APK on the device.

The important part is:

text 
Error during Sync: EOF

and:

text 
SyncService.doPushFile

This is usually an ADB/device communication or device-side installation problem, not a React Native JavaScript problem.

Step 1 — Check whether the device is still connected

Run:

cmd 
adb devices

Expected:

text 
List of devices attached
192.168.x.x:5555    device

If it shows offline, restart ADB:

cmd 
adb kill-server
adb start-server
adb devices

If using wireless ADB, reconnect:

cmd 
adb connect PHONE_IP:5555

Step 2 — Try installing the APK manually

First make sure the APK exists:

text 
android/app/build/outputs/apk/debug/app-debug.apk

Then install it manually:

cmd 
adb install -r "C:\\android\app\build\outputs\apk\debug\app-debug.apk"

If it succeeds:

text 
Performing Streamed Install
Success

then:

  • APK was built correctly
  • Android SDK is working
  • ADB can communicate with the phone
  • APK installation itself works

This is a very useful diagnostic test.

Problem 2 — Requested internal only, but not enough space

Example:

text 
Requested internal only, but not enough space

This means the phone does not have enough internal storage to install the APK.

Note

It is generally not a React Native code problem, Gradle problem, Android SDK problem, Metro problem, or Wi-Fi problem.

Check phone storage

You can use:

cmd 
adb shell df -h /data

If the available space is very low, free storage on the phone. Remove or move:

  • Large videos
  • Downloads
  • WhatsApp media
  • Unused applications
  • Old APK files
  • Other large files

Then try:

bash 
npx react-native run-android

Problem 3 — Installation works manually but run-android fails

Sometimes this works:

cmd 
adb install -r "C:\\android\app\build\outputs\apk\debug\app-debug.apk"

but:

bash 
npx react-native run-android

fails during installation.

If manual installation succeeds, check the ADB connection used by React Native/Gradle.

Run:

cmd 
adb devices -l

Then verify the exact device serial. Example:

text 
192.168.1.15:5555    device

You can also start the application manually:

cmd 
adb -s 192.168.1.15:5555 shell am start -n com.yourapp/.MainActivity

If the app opens, the APK installation is working.

Problem 4 — more than one device/emulator

Example:

text 
adb.exe: error: more than one device/emulator

This happens when ADB sees multiple devices/emulators.

Check:

cmd 
adb devices -l

Example:

text 
List of devices attached
emulator-5554          device
192.168.1.15:5555      device

Specify the device explicitly:

cmd 
adb -s 192.168.1.15:5555 install -r "C:\\android\app\build\outputs\apk\debug\app-debug.apk"

For other ADB commands:

cmd 
adb -s 192.168.1.15:5555 shell
cmd 
adb -s 192.168.1.15:5555 reverse tcp:8081 tcp:8081
Important

If adb devices -l shows only one device but ADB still reports more than one device/emulator, do not immediately assume that there are actually two phones. Check for multiple ADB installations/processes.

cmd 
where adb

For example:

text 
C:\Users\\AppData\Local\Android\Sdk\platform-tools\adb.exe
C:\scrcpy-win64-v3.3.3\adb.exe

Also check:

cmd 
tasklist | findstr /i "adb scrcpy"

If necessary, close applications using ADB, such as:

  • Android Studio
  • scrcpy
  • VS Code terminals running ADB commands
  • Other Android debugging tools

Then restart ADB:

cmd 
adb kill-server
adb start-server
adb devices -l

Problem 5 — adb reverse fails

React Native normally uses port 8081 for Metro.

For a USB-connected device, you can use:

cmd 
adb reverse tcp:8081 tcp:8081

For a wireless device:

cmd 
adb -s PHONE_IP:5555 reverse tcp:8081 tcp:8081

Example:

cmd 
adb -s 192.168.1.15:5555 reverse tcp:8081 tcp:8081

If you receive:

text 
adb.exe: error: more than one device/emulator

check:

cmd 
adb devices -l

and investigate multiple ADB connections/processes.

Problem 6 — App installs but shows Unable to load script

Example:

text 
Unable to load script.

If you're using USB on a physical device, make sure you
also run this command:

adb reverse tcp:8081 tcp:8081

This means the APK was installed and launched, but the React Native application cannot reach the Metro development server.

Note

This is different from an APK installation failure.

First check that Metro is running:

text 
Welcome to Metro v0.84.4

INFO  Dev server ready.

Then check:

cmd 
adb devices

If the device is connected, try:

cmd 
adb -s PHONE_IP:5555 reverse tcp:8081 tcp:8081

Problem 7 — Metro says No apps connected

Example:

text 
INFO  Reloading connected app(s)...

warn No apps connected.

This means Metro is running, but it does not currently detect a React Native app connection.

First check:

cmd 
adb devices

The phone should show:

text 
PHONE_IP:5555    device

Then make sure the application is actually running on the phone.

If necessary, launch it manually:

cmd 
adb -s PHONE_IP:5555 shell am start -n com.yourapp/.MainActivity

Problem 8 — Browser works but React Native still cannot load Metro

If opening http://PC_IP:8081 on the phone shows the Metro page, that proves the phone can reach the computer over the network.

For example, if the PC's Wi-Fi IPv4 address is 192.168.1.14, the phone can try:

text 
http://192.168.1.14:8081

If this opens successfully:

  • Phone can reach the PC
  • Port 8081 is reachable
  • Metro is running

If React Native still shows Unable to load script, then investigate the React Native/ADB connection configuration rather than assuming the router is blocking Metro.

Problem 9 — Wi-Fi/router prevents Metro access

If the phone cannot open http://PC_IP:8081, check:

A. Same network

The phone and PC should normally be connected to the same LAN. Example:

text 
PC:    192.168.1.14
Phone: 192.168.1.15

Both are on 192.168.1.x with subnet mask 255.255.255.0.

B. Windows Firewall

Windows Firewall can prevent other devices from accessing Metro. Make sure Node.js/Metro is allowed through the Windows Firewall, or allow the required connection when Windows asks.

C. Router client isolation

Some routers have features such as:

  • AP Isolation
  • Client Isolation
  • Wireless Isolation

These can prevent devices connected to the same Wi-Fi from communicating with each other. If the phone and PC cannot communicate directly, check the router settings.

Problem 10 — Manually install APK to separate the problems

This is one of the most useful troubleshooting techniques.

Build the APK:

bash 
npx react-native run-android

If the command fails specifically at :app:installDebug, try installing the generated APK manually:

cmd 
adb install -r "C:\\android\app\build\outputs\apk\debug\app-debug.apk"

If manual installation succeeds

The APK itself is valid and installation works. Focus on:

  • React Native CLI
  • Gradle install task
  • ADB device selection
  • ADB connection
  • adb reverse

If manual installation fails

Read the exact ADB error. For example:

  • not enough space → Free phone storage.
  • device offline → Fix ADB connection.
  • INSTALL_FAILED_... → Investigate the specific Android package/install error.

APK Installation Troubleshooting Flow

flowchart TD A[START] --> B{"Gradle builds APK?"} B -->|Yes| C[":app:installDebug"] B -->|No| D["Fix Gradle/SDK"] C --> E{"Installation result?"} E -->|"Succeeds"| F{"App starts?"} E -->|"Fails"| G["Read exact error"] F -->|"Yes"| H["Metro problem - Check Metro / port 8081"] F -->|"No"| G G --> I{"Error type?"} I -->|EOF| J["ADB issue"] I -->|"No space"| K["Free storage"] I -->|Offline| L["Fix ADB connection"]

Important Diagnostic Rule

Do not treat every run-android failure as a build failure. There are three separate stages:

flowchart TD A["React Native"] --> B["Gradle builds APK"] B --> C["APK installation"] C --> D["App launches"] D --> E["Metro connection"]

For example, BUILD SUCCESSFUL followed by Unable to install app means the build succeeded but installation failed.

Likewise, BUILD SUCCESSFUL and App launches followed by Unable to load script means the APK installation succeeded and the problem is now Metro connectivity, not APK installation.

Quick Commands (APK)

Check connected devices

cmd 
adb devices -l

Restart ADB

cmd 
adb kill-server
adb start-server

Install APK manually

cmd 
adb install -r "C:\\android\app\build\outputs\apk\debug\app-debug.apk"

Check phone storage

cmd 
adb shell df -h /data

Set up Metro reverse

cmd 
adb -s PHONE_IP:5555 reverse tcp:8081 tcp:8081

Start the application manually

cmd 
adb -s PHONE_IP:5555 shell am start -n com.yourapp/.MainActivity
Important

Most important rule: Always read the actual error at the bottom of the installation step. Warnings such as Gradle deprecation messages are usually unrelated to an APK installation failure. In the previous troubleshooting case, the real installation problem was insufficient internal storage on the device, not Gradle or React Native.

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