Android MS Defender child account cannot log in. Error: Invalid licence. please contact administrator

Hi, James Roodt

As your own Microsoft account works on your phone but fails on the child’s Samsung phone, this looks more like a device or parental-control conflict than a normal subscription problem. The main thing to check now is Google Family Link and cached sign-in accounts on Android.

Here are some suggestions you can try:

It is suggested that you temporarily remove the child’s Google account from the Samsung phone, then try signing into Microsoft Defender again. This does not delete the Google account itself. On the phone, go to Settings > Accounts, or Passwords and accounts > Google, select the child’s Google account, and remove it from the device. Then open Defender and sign in with the child’s Microsoft account. After Defender is set up, add the Google account back again.

Also check Android Settings > Accounts for any old Microsoft, Outlook, school, or work accounts and remove them temporarily. Defender may be picking up the wrong Microsoft sign-in token from the phone.

If Microsoft Authenticator is installed on the child’s phone, update it from Google Play, then restart the phone before trying Defender again.

If this still fails, I would test Defender on the same child Microsoft account using a different, non-Family-Link Android device if possible. If it works there, the issue is almost certainly Family Link or Samsung/Android account management rather than the Microsoft 365 Family license itself.

Thank you for your patience in reading, I hope this information has been helpful to you. 

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