What is this Bookings app error means

Hi @ANAND PRAKASH,

Welcome to the Microsoft Q&A forum.

Thank you for sharing.

I have attempted to reproduce the issue in my test environment and encountered the same behavior. When opening the Bookings app integrated within Teams, the system displays the same error code that you provided.

At the same time, I have also observed that some other users are experiencing a similar issue.

In this case, I recommend that you report the issue to Microsoft Technical Support so they can investigate and determine the root cause in more detail.

Note: To create a support ticket, your account must have Global Administrator permissions. If you do not have this role, please contact your organization's IT department for assistance with the steps below.

Steps to create a support ticket:

1. Go to admin.microsoft.com
2. Select Help & Support
3. Enter the title: Need support to investigate the Bookings app
4. Click Contact Support
5. Choose your preferred contact method

While waiting for Microsoft Support to investigate, you may temporarily continue using Bookings through the Outlook app integration or access Bookings via the web.

I hope this information is helpful.

If you have any questions or need further assistance, please feel free to share them in the comments so I can continue to assist you.

I look forward to your response.

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Looking at this error, the core issue here is a 401 Unauthorized error happening when Microsoft Bookings tries to load inside Teams. What's essentially happening is that when Bookings initializes, it reaches out to Microsoft's backend to fetch startup data in JSON format — but the server returned an incomplete or empty response, which caused that "Unexpected end of JSON" SyntaxError. The 401 status code behind it tells us that the authentication token either expired or wasn't passed correctly, so the server simply refused the request before it could even send proper data back.

The first thing you should do is fully sign out of Teams — not just close it, but properly sign out — and then log back in fresh. If that doesn't work, clear your Teams cache by navigating to %appdata%\Microsoft\Teams and deleting the Cache, blob_storage, and databases folders, then restart Teams. This fixes the issue in most cases because stale cached tokens are usually the culprit behind 401 errors like this one.

If the problem persists, try accessing Bookings directly through your browser at https://outlook.office.com/bookings — if it works there, then the issue is isolated to the Teams desktop client. Also worth checking with your IT admin whether the Bookings app is actually enabled for your account at the tenant level, because sometimes it gets blocked on a per-user or per-group basis through the Microsoft Admin Center. Your Teams version looks up to date, so that's not the concern here — it's almost certainly a session or policy issue.