Not able to run Mobile App on Android Emulator.

Hi, I have just started using Titanium Studio and have installed the latest version 3.1.1. I have also installed the required iOS and Android SDK, as my Titanium Dashboard shows a green tick next to both the Android SDK and iOS SDK.

But now when I am running the simple default mobile application in Android Emulator I am getting the error -

[ERROR] Exception occured while building Android project:
[ERROR] Traceback (most recent call last):
[ERROR]   File "/Users/bablydas/Library/Application Support/Titanium/mobilesdk/osx/3.1.0.GA/android/builder.py", line 2528, in <module>
[ERROR]     builder.build_and_run(False, avd_id, debugger_host=debugger_host, profiler_host=profiler_host)
[ERROR]   File "/Users/bablydas/Library/Application Support/Titanium/mobilesdk/osx/3.1.0.GA/android/builder.py", line 2264, in build_and_run
[ERROR]     self.manifest_changed = self.generate_android_manifest(compiler)
[ERROR]   File "/Users/bablydas/Library/Application Support/Titanium/mobilesdk/osx/3.1.0.GA/android/builder.py", line 1404, in generate_android_manifest
[ERROR]     '-I', self.android_jar], warning_regex=r'skipping')
[ERROR]   File "/Users/bablydas/Library/Application Support/Titanium/mobilesdk/osx/3.1.0.GA/android/run.py", line 38, in run
[ERROR]     print "[DEBUG] %s" % subprocess.list2cmdline(args_to_log)
[ERROR]   File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 587, in list2cmdline
[ERROR] TypeError: argument of type 'NoneType' is not iterable
[ERROR] :  Build process exited with code 1
[ERROR] :  Project failed to build after 32s 47ms