Good day!
Welcome to Microsoft Community. Thank you for sharing your concern with us today and we hope that all is well.
I understand your concern. The error message you are seeing may occur due to a temporary interruption in the Microsoft Defender services on your Android device. Restarting the app a few times can sometimes resolve this issue. However, if the problem persists, it is recommended to sign in again to reauthorize the app and ensure the services work smoothly. If you continue to experience difficulties, please let me know so I can assist you further.
Hope this helps!
Fritz-Bald
Microsoft Community
Moderator