Copilot Studio WhatsApp not responding - Event Subscription provisioning failure

Hi @Victor Daniel Tomás Rodríguez

Thank you for the detailed information — this really helps narrow down the issue.

The behavior you're describing is consistent with a known intermittent failure during Event Grid Event Subscription provisioning when publishing the WhatsApp channel in Copilot Studio. ACS is correctly receiving messages and the System Topic is created, but the subscription needed to forward events to your agent isn't being provisioned.

How the flow is supposed to work

WhatsApp > Azure Communication Services > Event Grid (System Topic + Event Subscription) > Copilot Studio agent.

Because the Event Subscription is missing, incoming messages never reach the agent, so it appears unresponsive.

Steps to Resolve

1. Validate Prerequisites & Permissions

• Make sure the account you're using has Owner permissions at the Azure Subscription level (Contributor is often insufficient).
• Confirm the Microsoft.EventGrid resource provider is registered in your subscription.

2. Reconnect & Re-publish the Channel (Recommended First Step)

• In Copilot Studio, go to your agent > Channels > WhatsApp (ACS).
• Disconnect the channel.
• Wait 5–10 minutes.
• Reconnect the same WhatsApp number and re-publish the agent.

This usually forces a fresh provisioning attempt and resolves the missing subscription.

3. Verify the Event Subscription After republishing:

• Go to your Azure Communication Services resource > Events.
• Check that an Event Subscription now exists under the System Topic.

4. Manual Event Subscription (if reconnecting doesn't work) You can create the subscription manually:

• In the ACS resource > Events > + Event Subscription.
• Event Types: AdvancedMessageReceived (and related messaging events).
• Endpoint Type: Webhook.
• Endpoint: Copy the webhook URL from your Copilot Studio WhatsApp channel settings.
• Authentication: No authentication.

Reference :

https://learn.microsoft.com/en-us/azure/communication-services/concepts/advanced-messaging/whatsapp/whatsapp-channel-prerequisites

https://learn.microsoft.com/en-us/azure/communication-services/quickstarts/advanced-messaging/whatsapp/handle-advanced-messaging-events

https://learn.microsoft.com/en-us/microsoft-copilot-studio/publication-add-bot-to-whatsapp

Kindly let us know if the above helps or you need further assistance on this issue.

Please "upvote" if the information helped you. This will help us and others in the community as well.

Hi @Victor Daniel Tomás Rodríguez

Thanks for the thorough update I appreciate you confirming the prerequisites and retrying the disconnect/reconnect steps multiple times. Sorry this is still blocking you; it does sound like an internal provisioning hiccup preventing the Event Subscription (and thus the webhook) from being created automatically.

Quick Workaround to Get It Working

Even when the webhook URL isn't immediately visible in the channel settings, you can usually find it here:

1. In Copilot Studio, open your agent > Channels > select the WhatsApp (ACS) channel.
2. Look under Advanced settings, Callback information, or the connection details section for the webhook/callback URL (it often follows a pattern like https://*.botframework.com/api/v1/bots/... or ends in /api/updates).

If it's still not showing, try:

• Going to the Microsoft Copilot Studio Admin Center (powerplatform.microsoft.com) and reviewing the channel configuration there.
• Republishing the agent once more after a short wait.

Once you have the URL, manually create the Event Subscription in your Azure Communication Services resource:

• Go to your ACS resource > Events > + Event Subscription.
• Name: Something like copilotstudio-whatsapp.
• Event Types: Select Microsoft.Communication.AdvancedMessageReceived (and IncomingMessageReceived if available).
• Endpoint Type: Webhook.
• Endpoint: Paste your Copilot Studio webhook URL.
• Authentication: No authentication.
• Add an advanced filter for your specific WhatsApp phone number/channel ID (highly recommended).

You can also do this via Azure CLI for precision.

After creating it, the subscription should go to Succeeded. Send a test WhatsApp message and check the agent's responses and Event Grid delivery metrics.

Reference :

https://learn.microsoft.com/en-us/microsoft-copilot-studio/publication-add-bot-to-whatsapp

https://learn.microsoft.com/en-us/azure/communication-services/quickstarts/advanced-messaging/whatsapp/handle-advanced-messaging-events

https://learn.microsoft.com/en-us/azure/communication-services/concepts/advanced-messaging/whatsapp/whatsapp-channel-prerequisites

Kindly let us know if the above helps or you need further assistance on this issue.

Please "upvote" if the information helped you. This will help us and others in the community as well.

Hi @Victor Daniel Tomás Rodríguez

Just following up to see if your issue has been resolved or if you had a chance to review my earlier comment?