google app engine error ,and i can't open it now.(python)
Not enough points to provide a comment on the answers above hence the stand alone answer. If you delete the ini files as per the other answers the pathways to your projects in the launcher will likely also be gone. In my case however I simply moved the ini files out of the C:\Users\your username\Google directory and then after opening and closing the launcher successfully once I reinstated the ini files into the Google directory again, after which the launcher worked and the project pathways were retained.
the error is :

Errors occurred
See the logfile 'D:\Program Files\Google\google_appengine\launcher\GoogleAppEngineLauncher.exe.log' for details
Why?