Urgent! I can't connect to my emulator for the life of me

Hey everyone
I've been trying to connect to my emulator for the last hour to do a project that I need to do (it's my first time trying using this app) and even after downloading the emulator properly and restarting my computer, every time I press Emulator on the drop down connect menu it doesn't work. I'm using a Mac and I just get the message "Starting the Android Emulator" until another screen pops up that says "Unable to retrieve the version of aiemulator saved on your computer." I just keep getting this message and I feel like I've done everything, does anyone know anyway I can connect to the emulator?

If I manually open aiStarter on Terminal then I get this message:

Last login: Wed Feb 24 09:56:11 on ttys000

MacBook-Air:~ jackbreuhaus$ /Applications/AppInventor/commands-for-Appinventor/aiStarter ; exit;

Running aiStarter version 3.0

Bottle server starting up (using WSGIRefServer())...

Listening on

Hit Ctrl-C to quit.


Traceback (most recent call last):

File "aiStarter.py", line 131, in

File "bottle.py", line 2389, in run

File "bottle.py", line 2086, in run

File "wsgiref/simple_server.py", line 151, in make_server

File "SocketServer.py", line 417, in init

File "wsgiref/simple_server.py", line 48, in server_bind

File "BaseHTTPServer.py", line 108, in server_bind

File "SocketServer.py", line 431, in server_bind

File "socket.py", line 228, in meth

socket.error: [Errno 48] Address already in use

[1121] Failed to execute script aiStarter

No matching processes belonging to you were found

No matching processes belonging to you were found

  • daemon not running; starting now at tcp:5037

  • daemon started successfully

error: no emulator detected

Killed emulator

Killed adb


Saving session...

...copying shared history...

...saving history...truncating history files...


[Process completed]

Does that have something to do with my issues?

I am not a Pro, so i cant really tell where the issue lays.
But I will tell you, what i do to use the android emulator on my system(win10), maybe that helps you to find your issue:

(Normal Starting)

  1. Starting Porgram aiStarter
  2. Open AppInventor Platform
    3 Click Connect -> Emulator
  3. Waiting... Finished
  4. Android Emulator Running and Project Running

Do you have an Android device? (that would be much easier)

If not, you could also use an android emulator like bluestacks(if you cant resolve the issue with AppInventor emulator).

Best Regards,

Thanks for the response! I ended up just choosing a whole different project, but I was using an emulator cause I don't have an android device. I have no clue why the AppInventor emulator wasn't working, but int the end it doesn't matter too much. Thanks!

On macOS aiStarter runs in the background and starts running when you log into your machine. The error you have here:

is because the background version already is running and listening on the port in question. You can just select "Connect > Emulator" in the menu to initiate the emulator connection.

Hello Jack
If you are testing App Inventor for iOS this might not be an appropriate comment:
Have you tried using the Companion? It's often better than the Emulator because (a) it runs your App on your phone so you can see the GUI layout, test the ergonomics, response speed etc and (b) it tolerates changes in the Designer and Blocks in real time.