Unity editor version: 2019.2.17f1
Firebase Unity SDK version: Version 6.8.1
Firebase plugins in use (Auth, Database, etc.): Analytics
Additional SDKs you are using (Facebook, AdMob, etc.): Admob, Goggle Play Services
Platform you are using the Unity editor on (Mac, Windows, or Linux): Windows 7 Ultimate SP1
Platform you are targeting (iOS, Android, and/or desktop): Android
Scripting Runtime (Mono, and/or IL2CPP):IL2CPP

1. I created empty project (Nothing in there. Only test for firebase, admob, GPGS and sample code from firebase.google.com)
2. I downloaded goggle-services.json file from console.
3. When I start to Unity then I got this error:

Generation of the Firebase Android resource file google-services.xml from Assets/google-services.json failed. If you have not included a valid Firebase Android resources in your app it will fail to initialize.

D:/Project Unity/Unity Test (Published)/Assets\..\Assets/Firebase/Editor/generate_xml_from_google_services_json.exe -i "Assets/google-services.json" -l.

Error loading Python DLL: C:\Users\sadrag\AppData\Local\Temp\_MEI105202\python27.dll (error code 14001)

4. And real-time statistics not working on the console.
5. I do not receive this error in version 6.7.0.