Unable to install the new beta for the HomePod 15 from the Appleseed site. I get a popup message "install profile failed Error 4001
Install Profile Failed HomePod 15
I got this message also. Resolved by: 1)removing the previous beta profile, 2)restarting the HomePod, then 3)installing the IOS 15 Beta profile. My HomePods and minis updated just fine to IOS 15 afterwards
Seems the previous HomePod beta was still hanging around even though the app showed no signs of the software. Had to reset the Home app and everything was fine afterward.