90403: [Autopilot] Signature validation failed

This error occurs when Twilio cannot validate an Autopilot assistant signature because the assistant and the Messaging Service or Voice service are owned by different Twilio accounts that do not share a parent and subaccount relationship. Twilio keeps resources separated by account, so the service account must own the assistant directly or through the same account hierarchy.

• The Autopilot assistant was created in a different Twilio account than the Messaging Service or Voice service.
• The assistant account and the service account are unrelated accounts instead of a main account and one of its subaccounts.
• You are working with subaccounts, but the assistant and service were created or managed under different account credentials, so they are not in the same account hierarchy.

• Reconfigure the integration so the Autopilot assistant and the Messaging Service or Voice service belong to the same Twilio account.
• If the service must stay in its current account, move the assistant by exporting it and importing it into that account or into one of its subaccounts.
• Review your account hierarchy before reconnecting the assistant. A main account can own subaccounts, but resources remain separated by account and must be managed from the correct account context.

• Subaccounts
• Webhooks security
• Messaging Services