It looks like your project was configured to use Python 3.3 but you currently only have 3.4 installed.
In Solution Explorer, you should see an entry in your project labeled "Python Environments" that contains "Unknown Python 3.3". If you remove this item, it should default to 3.4. (You can also right-click Python Environments and use Add/remove
Python Environments to add 3.4 in.)
We ought to be providing a different error message in this case.