App Inventor cannot connect to emulator

Question

Started evaluating MIT App Inventor (ver 2.2) on Windows 7 (from Administrator account). Since I don't have Android devices, I have to use an emulator.

aiStarter.exe and emulator.exe both work when explicitly started, but
when I start aiStarter.exe and ai2.appinventor.mit.edu/#5440960545685504 on Chrome and then do Connect/Emulator, emulator.exe is not started, and aiStarter disply messages like:

127.0.0.1 - - [16/Dec/2014 04:15:13] "GET /echeck/ HTTP/1.1" 200 38
The system cannot find the path specified.
Problem checking for devices : status 1 

I tried disabling Chrome extensions, and trying to start ai2.appinventor.mit.edu from FireFox and Maxthon browsers, with identical negative results.
Both Googling and searching appinventor.mit.edu didn't help.

1. What is the failed path in the error message referring to?
2. Any suggestions how to debug App-Inventor/emulator startup failure?

Answer 1

Since no remedy seemed to help, I decided to start from a clean slate.

I went to http://appinventor.mit.edu/explore/ai2/update-setup-software.html and followed "How to Update the App Inventor Setup Software"

1. Uninstalled current App Inventor
2. Booted my machine
3. Downloaded the latest Windows installer from http://appinv.us/aisetup_windows
4. Installed the AppInventor_Setup_Installer_v_2_2 (1).exe that I downloaded, accepting all the installer's defaults. The installation directory was chosen by the installer in C:\Program Files (x86)\AppInventor
5. Logged out and after logging in again - aiStarter is running
6. Killed all the BlueStack processes
7. Tried Connect/Emulator. Emulator won't start, though it's not failing as previousely
8. Started emularor using run_emulator.bat
9. After a few tries, finally emulator is syncing with App Inventor 2