Teams Azure bot Error 403 "The bot is not part of the conversation roster"

Question

I'm currently troubleshooting an intermittent issue with my Microsoft bot, which is registered in Azure and integrated with Microsoft Teams. Occasionally, when the bot attempts to send notifications to Teams, it encounters the following error message: 

Error 403 "The bot is not part of the conversation roster"

This doesn't happen consistently, which makes it difficult to pinpoint the root cause. I'm looking for guidance or potential solutions to help resolve this issue and ensure reliable communication between the bot and Teams.

Answer 1

Hi Kristina Dennis

Thanks for reaching out to Microsoft Q&A forum support

Based on your description, I understand that you're encountering an intermittent issue where your Microsoft bot registered in Azure and integrated with Microsoft Teams, occasionally fails to send notifications and returns the error: "403: The bot is not part of the conversation roster.

This error typically occurs when the bot attempts to send proactive messages to a Teams conversation it is not currently a member of. The inconsistency suggests that the bot may be removed, blocked, or not properly added to certain chats or channels, either due to user actions, policy changes, or configuration gaps in Azure Bot Service. Bots installed only in the General channel of a team do not automatically gain access to other channels unless explicitly added. Additionally, misconfigured service URLs or missing permissions in Azure can silently cause the bot to lose access intermittently.

Based on my knowledge, to work around this issue, you can consider the following approaches:

• Verify and maintain bot membership in conversations Ensure the bot is explicitly added to all relevant Teams channels or chats. If the bot was removed or blocked, re-add it via Teams settings under “Manage Apps.”
• Implement presence checks and retry logic Use the Bot Framework SDK to verify the bot’s presence in the conversation roster before sending messages. If absent, initiate or rejoin the conversation programmatically. Adding retry logic can help handle transient failures.
• Review Azure Bot configuration and permissions Confirm that your bot’s Azure registration includes the Microsoft Teams channel and is authorized for proactive messaging. Double-check the service URL and ensure it matches the Teams environment where the bot is deployed.

If the issue persists after that, I recommend raising a support ticket with the Azure Support team. As far as I know, this error seems to be related to Azure configuration, and they have the necessary tools and access to investigate further. Since we don’t have those tools available on the forum side, I really appreciate your patience and understanding. 

For more details, you can also refer to this article: How to create an Azure support request - Azure supportability | Microsoft Learn 

I hope my answer will help you, if you need any further support, kindly let me know in the comment section.

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".     

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.