PyCharm - Unresolved library 'staticfiles'

In my case this happened when PyCharm couldn't find settings.py file. This because I have - local_setting, prod_setting etc. So I go to File -> Settings -> Language & Framworks -> Django -> Settings and select appropriate file with setting of django project.

It turned out that the dynamical creation of INSTALLED_APPS confuses PyCharm somehow. It cannot resolve certain dependencies such as the template_tags if these are created dynamically. Seems like one has to decide whether to have a nice code navigation or static INSTALLED_APPS.