aiStarter stopped working

MIT App Inventor Help
1

Hi,
Followed the instructions on http://appinventor.mit.edu/explore/ai2/mac for osx 10.10 and up, currently on 10.15/Catalina.
Few things to note that deviated from the posted instruction.

  1. Catalina prevented the installation, required to explicitly allow to run the installer. After this it installed per the instructions.

  2. At the completion of the installation Catalina required a reboot of the operating system. Rebooted

  3. Logged into appinventor, started an app and the browser is at the designer page

  4. went to the folder and 2xClicked on aiStarter and this error appeared
    Running aiStarter version 3.0
    Bottle server starting up (using WSGIRefServer())...
    Listening on http://127.0.0.1:8004/
    Hit Ctrl-C to quit.
    Shutdown...
    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
    [2014] 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

Closed the terminal window and attempted again, the exact same error occurred.
Left the second attempt terminal open
Opened a second terminal and ran
sudo lsof | grep 8004
It shown 2 process, the aiStarter and the grep

Closed the aiStarter failed terminal
On the second terminal ran the sudo lsof | grep 8004 and it shown 1 process, the grep

python -m SimpleHTTPServer 8004
response
Serving HTTP on 0.0.0.0 port 8004 ...

opened a new tab on the browser and entered 127.0.0.1 port 8004
Showing contents of the current directory.

Please advise.
Thank you

2

aiStarter runs in the background on macOS, so you don't need to start it like you would on Windows. This is the reason for the "Address already in use" error. If you really want to run it in the terminal, for example to see potential error messages, then you should launch the terminal and run:

launchctl unload /Library/LaunchAgents/edu.mit.appinventor.aiStarter.plist

This will stop the version running in the background. To start it again, run:

launchctl load /Library/LaunchAgents/edu.mit.appinventor.aiStarter.plist