It seems that the virtual environment is not working. You have installed the script flags package, but when you run the script, it is still looking for it in C:\Python3.4. You can give us more information so that we can understand where this is wrong. (How do you install it, how do you activate virtualenv, reinstall virtualenv, close the cmd shell, and try to work again?)
, from flask.ext.extension import xxx - . from flask_script import Manager, Server, script 2.0.5