Reset Default Keychain breaks TouchID without any information to the user

Number:rdar://29453789 Date Originated:11-30-2016
Status:Open Resolved:No
Product:macOS + SDK Product Version:10.12.1 - 16B2659
Classification:Serious Bug Reproducible:Always
When using Keychain Access to reset the default keychain, the entries located for TouchID are lost. This causes fingerprints to still show that they are valid, but you cannot use Touch ID to unlock the machine or use it for any other administrative tasks.

Reproduce steps
1. Configure Touch ID either through SetupAssistant or System Preferences -> Touch ID
2. Lock screen and authenticate to ensure Touch ID is functioning.
3. Open /Applications/Utilities/Keychain and go to Preferences -> Reset My Default Keychain
4. Create a new login.keychain
5. Reboot
6. Login and attempt to use Touch ID for administrative tasks or subsequent unlocks.

Expected Results
1. Keychain Access should inform the user that they will need to re-configure any previously configured fingerprints.
2. A sub process should remove any fingerprints configured for that particular user.

Actual Results
Keychain is reset and System Preferences -> Touch ID shows valid fingerprints. The user can no longer use Touch ID.


Please note: Reports posted here will not necessarily be seen by Apple. All problems should be submitted at before they are posted here. Please only post information for Radars that you have filed yourself, and please do not include Apple confidential information in your posts. Thank you!