We have reached out to Avalara support and identified the issue, which was a validation error with one of their APIs. The original problem no longer persists, but address validation may have an increased rate of error for the next 24 hours.

We have disabled Avalara address validation temporarily and investigating this issue with Avalara.

We are continuing to investigate this issue.

We are investigating failures in Avalara based address validation. This is affecting only customers who have enabled Avalara address validation. We will update shortly.