Add Configuration is greyed out because maybe you haven't added python path to the project try adding it and you should be clear before posting questions maybe some code and pictures will help. Try this and let me know if this have solved your problem.
I opened a series of files to edit them and my run button is greyed out. I can't figure out exactly why, but I think it has something to do with the "add configuration" prompt nest to the run button. I don't know how to add a configuration and don't want to mess up my editor. I have the newest version of the community version of PyCharm.
Adding a run configuration in PyCharm for a python project