Smart Lock For Passwords Not Working On Certain Phones, Error Message "no Eligible Accounts On This Device"

When I run the quick-start sample from: https://github.com/googlesamples/android-credentials/ On a Nexus 6 running Marshmallow, the credentials are saved successfully. However, on

Solution 1:

Straight after I posted this, I found my answer.

The issue is not with the flavour of Android, but with the Google account settings. The account that I was using on the Samsung Note 5 had a custom passphrase encrypting passwords, which is not supported by Smart Lock for custom passwords.

I found the settings for Smart Lock for Passwords under a separate place from the other Smart Lock settings on the Samsung. They were under Accounts -> Google -> scroll to very bottom: