Pycharm 5.0.1: Scanning files to index taking forever

I am using PyCharm Community Edition 5.0.1 It was working fine till yesterday. But it has been stuck at 'Scanning files to index' for a very long time now. Since yesterday.

I have tried re-installing it, and also tried invalidating cache.

I can make changes to programs and use it as a text editor but unable to run any file. Can anyone help? Thanks.

Exclude the folders you do not want to index. You can do this by right-clicking the folder you want to exclude, then choose Mark Directory As > Excluded and PyCharm will not index those files.

From: stackoverflow.com/q/34976058