Invalid Python SDK Error while using python 3.4 on PyCharm

Question

When I switch my PyCharm to use Python 3.4.3 I am getting the error:

Invalid Python SDK

Also PyCharm does not automatically find

Answer 1

I go the same error message in Windows version of PyCharm after I re-installed Python (3.5) on a different location. The problem was that most of my existing virtual environments registered in PyCharm were still referencing the old installation of Python.

I resolved it by deleting these existing virtual environments and creating a new one. If deleting existing interpreters (in virtual environment) is not an option, you should be able to modify them instead in File | Settings | Project Interpreter