Amazon has identified the root cause of the issue and are putting mitigations in place as they work towards a full recovery.
Since we redeployed our CloudFront distribution, we've continued to monitor the application and we're no longer seeing the errors that were occurring earlier.
Any users who are still seeing errors should clear their browser cache before trying again. For further assistance, please contact our support team via help.pimberly.com or support@pimberly.com.