由于AttributeError，导入matplotlib.pyplot在PyCharm中失败：模块'PyQt5.QtGui'没有属性'QApplication'

I wanted to change my python compiler to "newer" one (within one project) and use some additional packages with conda. After the installation all my packages worked fine and I could use the console, however matplotlib.pyplot fails to import since then. And throws the following error: I wanted to change my python compiler to "newer