KivyMD Error: ValueError: KivyMD: App object must be initialized before loading root widget

Question

How do I fix this error:

ValueError: KivyMD: App object must be initialized before loading root widget.

My Code:

kv = Builder.load_file("my.kv")

class MyMainApp(MDApp):

    def __init__(self, **kwargs): 
        App.__init__(self)   
        theme_cls = ThemeManager()


if __name__ == "__main__":
    MyMainApp().run()

Everything online says that I have to move my .kv file inside my .py file. Is there a way to keep my .kv file?

Answer 1

https://kivymd.readthedocs.io/en/latest/themes/material-app/#kivymd.app.MDApp.theme_cls

class MainApp(MDApp):
    def build(self):
        self.theme_cls.primary_palette = "Teal"