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

This also happened to me. I renamed a repository and then my virtual environment got stuck in the old path.

I grepped all configuration files and could not find any reference to the old one.

What finally solved the problem was to clear caches with the option File > Invalidate Caches / Restart...: