I was upgrading my project from 2019.4.8.1 to 2020.2.0b12 (problem still exists in b13) and got above error message when opening the services tab or selecting Services in the Project Settings
This is a bug as I cannot configure Services i.e. In App Purchases with this editor version
@kubimtk Did you find any solution to it ?,Did you find any solution to it ?
Delete ProjectSettings (most parts), Temp, Packages und Library (full) did help somehow