The Python Package Index (PyPI) has recently upgraded its caching infrastructure, which broke our integration with their service. We contacted them to restore this functionality temporarily, and now we’ve prepared a hotfix to make sure earlier PyCharm versions will continue to work into the future.
If you are using PyCharm 5 or PyCharm 2016.1 please update today (Help | Check for Updates) to make sure you won’t be affected when PyPI deactivates their now deprecated API.
Full installers for previous versions of PyCharm can be downloaded from the previous versions confluence page.
-PyCharm Team