I have the latest PyCharm CE and am using it with virtualenv. I have defined the interpreter as the interpreter in the virtualenv. The Project Inte
Open up Preferences -> Project -> Project Interpreter, do you see the module there?
If yes, you might have another file somewhere in your project have the same name as flask.ext.login, this prevents pycharm from locating the actual module.
If no, you can click on the ... beside your interpreter and select more..., select your interpreter and at the bottom (beside the filter), click the Show paths for the selected interpreter, you can add the path of your module there.