Symptom

You are in Home Assistant and when trying to log into Home Assistant Cloud, you are getting a message saying "Authentication failed", with something like "Unexpected error - software token MFA". You can't log into Home Assistant Cloud.

Cause

"Authentication failed", with "Unexpected error - software token MFA" indicate that the software version on your Home Assistant is too old to support MFA for Home Assistant Cloud.

Resolution

1. In Home Assistant, check if you have Home Assistant version 2025.1.0 or later
   • Open Settings > About.
2. If you're version is older, choose one of the following options:
   • Option 1: Update Home Assistant.
   • Option 2: Disable MFA for Home Assistant Cloud.

Related topics

• Disable MFA
• Update Home Assistant