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android – Error "The connection to adb is down, and a severe error has occurred."

Posted by: admin March 10, 2020 Leave a comment


I’ve spent days trying to launch any Android program. Even “Hello World” gives me the same error:

“The connection to adb is down, and a severe error has occurred”.

I’m running Eclipse v3.5 (Galileo), Google APIs 2.2.8, on a Windows XP machine.

I’ve used all the tricks I can find on the web: the command line “adb kill-server”, the DDMS “reset ADB”, I started the emulator both before and after Eclipse, and searched for ports being used by other programs.

What is going on here? Is there a magic combination of versions of Eclipse, Java, ADB, emulator, and whatever else that works?

How to&Answers:

Try the below steps:

  1. Close Eclipse if running
  2. Go to the Android SDK platform-tools directory in the command prompt
  3. Type adb kill-server (Eclipse should be closed before issuing these commands)
  4. Then type adb start-server
  5. No error message is thrown while starting the ADB server, then ADB is started successfully.
  6. Now you can start Eclipse again.

It worked for me this way.

Restart your phone as well!



Open Task Manager → Processes → adb.exe → End Process → restart Eclipse

This worked for me.


Open Task Manager → Processes → eclipse.exe → End Process → restart Eclipse


Open up the Windows task manager, kill the process named adb.exe, and re-launch your program.


[2012-07-04 11:24:25 – The connection to adb is down, and a severe error has occurred.
[2012-07-04 11:24:25 – You must restart adb and Eclipse.
[2012-07-04 11:24:25 – Please ensure that adb is correctly located at ‘/home/ASDK/platform-tools/adb’ and can be executed

I realized the folder of the project in Eclipse was closed. I expanded the directory and the project launched. I know this may sound like a “no-brainer”. I had the .java files open on the workspace, and that was enough to make me think the project was open.


I tried this using Eclipse Juno and it worked fine:

  • From the dropdown of the Run icon, select option Run Configuration.
  • Make sure your project is selected
  • Go to tab Android
  • Under section Launch Action, select Launch Select the package name
    and voila! try running your application.

UPDATE: It also helps to kill the process adb.exe from the task manager and restart it. adb.exe can be found here: Android\android-sdk\platform-tools.

Good luck


Update your Eclipse Android development tools. It worked for me.


Make sure it’s not running in the task-manager processes. If so, end the process and then start it from a command prompt as in a previous answer. This worked for me.


In my situation: I have the same warning:
The connection to adb is down, and a severe error has occured

I have found the solution:

The adb.exe was moved from: android-sdk-windows\tools\adb.exe to

Only thing. Move file adb.exe to \tools. And restart Eclipse.


I know this question has already been answered, but thought I might add that I found the problem to be folder permissions on my android-sdk directory.

I tested it out by granting Full Control to Everyone (dodgy, I know…), and the problem went away. I am not sure yet what the specific mix of permissions might be that it was looking for, but I assume some or other service in Eclipse didn’t have execute permissions on adb.exe. That said, I’m a complete noob to this – just wanted to put it out there in case someone else had some insights into this.

I am running Windows 7, 64-bit, 4.2.0 Eclipse, and 20.0.0v201206242043 ADT.


  1. Go to the folder platform-tools in cmd folder platform tools available in the Android folder where you have Android backup files.

  2. Type the following

    adb kill-server


    adb start-server

    then type

    adb devices
    adb kill-server

You can now see your device.


This problem has been plaguing me for days until I finally figured out what was causing it. It got so bad I couldn’t even update my apps even after trying all the above suggestions.

HTC Sync also runs a process called adb.exe. HTC Sync is an optional program available when installing the HTC USB driver. I had recently updated my installation of the HTC bundle and apparently hadn’t installed HTC Sync before. Checking properties on adb.exe in the Task Manager showed it to belong to HTC Sync, not Android.

As soon as I uninstalled HTC Sync from the control panel the problem disappeared! (It’s listed separately from the USB driver so that can stay.) I never saw more than one instance of adb.exe running. I’m curious to know if people having to kill the process from Task Manager, check to see if it’s actually the Android process you are killing?

Please read user comments (I too have a HTC Thunderbolt):


Simply go in Task Manager (windows users) and kill the abd.exe (it is remaining active somehow).
After that start Eclipse.

The error

“The connection to adb is down, and a severe error has occured”

happened after installing plugin for Android of Netbeans. After closing Netbeans the process abd.exe remained active. When you want to start again Eclipse … you will get the error.

You have to manually kill the adb.exe and then start Eclipse.

It worked for me.


I had the same problems, and it turned out that my antivirus program (Comodo) sandboxed the adb.exe, and that is why it didn’t work. I closed the antivirus, and it worked just fine. Consider that.


My problem was that my firewall was preventing ADB from binding to the port it wanted to.


I had the same problem

  1. I entered Task manager -> find adb.exe -> end process
  2. Go to the Android SDK tools directory in Command Prompt double click adb.exe

That’s all


I am running Eclipse Neon2. on Mac OS 10.12.4 and I experienced this issue after recently upgrading my Android SDK to the latest “SDK Tools” (v 25.2.5), “Platform tools” (v 26) and “Build Tools” (v 26) and moving one of my development projects to Android Studio.

Unfortunately none of the many answers here worked for me.

What did work was to create a separate copy of the Android SDK in a different folder and then point Eclipse to it via “Preferences –> Android”. You will have to use an older version of the SDK as indicated in this SO answer.

Once you’ve downloaded the separate version of the SDK and put it in a different folder than your main Android SDK, launch the SDK Manager (via <separate-sdk>/tools/android) and install the required “Platform tools”, “Build-tools” and Android versions. There are two important things to observe here though:

  1. Make sure that you do not upgrade your “SDK Tools” beyond the version that’s already installed!

  2. Make sure that you install a version of the “Build tools” that is less than 26!

Otherwise you may run into this issue.


  1. Go to the tools folder of your Android SDK
  2. Run emulator.exe -avd <your avd>. It will take some time for the emulator to run.
  3. Once you see the homescreen on your emulator, open Eclipse and run your program again…


I had a similar problem. I found out that there was another adb.exe running which was started from BirdieSync (Sync Tool for Thunderbird). I found out with Process Explorer from Sysinternals, that Windows was running another incompatible adb.exe. Just put the mouse cursor above the process (in Process Explorer), and you’ll see which adb.exe is started.

I had to kill the BirdieSync process as well, because it started the wrong adb.exe again.

Then I could start the right adb.exe, and it worked fine.


The killing of the mysteriously running abd.exe worked. This sudden roadblock stopped me for a long time. I was doing all sorts of command line stuff and removed the lock icon from my user folder, but nothing worked until your simple suggestion of looking for the abd in the running processes of the task manager and killing it.

Another newbie roadblock I discovered an answer to: don’t run Eclipse when any file other than the main .java file is active. If you run it when, for example, the main.xml file is active, you will get unhelpful error messages, an odd file created like main.xml.out, and it wont run.


I found the path of the SDK (Preferences* → AndroidSDK Location) was the cause. My SDK path was the following:

C:\Program Files (x86)\Android\android-sdk

The spaces in the path is the problem. To get it to work, you must change Program Files (x86) to Progra~2

The complete right path is C:\Progra~2\Android\android-sdk.

Now it should work.


The previous solutions will probably work. I solved it downloading the latest ADT (Android Developer Tools) and overwriting all files in the SDK folder.


Once you overwrite it, Eclipse may give a warning saying that the path for SDK hasn’t been found, go to Preferences and change the path to another folder (C:), click Apply, and then change it again and set the SDK path and click Apply again.


Close Eclipse

Use this in the terminal:

sudo killall -9 adb

Run Eclipse.


If you are using the Genymotion emulator:

Make sure that the SDK path used for Genymotion is also the same path used for the Eclipse.

This error also occurs if those two paths are different.


I’ve tried the above methods, end the adb process through task manager and all, it didn’t work. But when I ran the adb.exe file as admin it worked fine.


Here is a script I run to restart adb (Android Debug Bridge) server:

#!/usr/bin/env bash

## Summary: restart adb (Android Debug Brdige) server.

## adb binary full path

if pgrep adb >/dev/null 2>&1
    echo "adb is running"
    echo "terminating adb ..."
    $ADB_BIN kill-server
    if pgrep adb >/dev/null 2>&1
        echo "did not work"
        echo "kill adb processes by killall"
        killall -9 adb
        echo "terminated"
    echo "adb is not running"

echo "starting adb ..."

$ADB_BIN start-server

echo "adb process:"

echo `pgrep adb`

echo "done"



Last time I faced this problem, was solved with adb restart. If you have tried adb kill-server and adb start-server with no luck you might want to try this. When again I faced the same issue I tried all the above answers, with no luck, and this was the last option to try. It did work like a charm.

Goto Android SDK Manager >> Install the essential packages.


maydenec is correct (in my case…). The file was moved.

I even found this file:

C:\Program Files (x86)\Android\android-sdk\tools\adb_has_moved.txt

Which explained this issue.

Suggestions in this file:

  1. Install “Android SDK Platform-tools”.
  2. Please also update your PATH environment variable to
    include the “platform-tools/” directory.


It worked for me to start my AVD emulator first (from the AVD manager), and then to run my program. The other stuff mentioned here.

(Restarting the ADB server didn’t work though.)


Eclipse → preferencesAndroidNDK

Check the “NDK Location” path is set correctly, and use the browse button to set it.


AndroidSDK → Platform ToolsKill did not work.

But after restarting my computer, it worked.