Unable to sync calendars with Google workspace

Dear @Ferran Gimenez,

Thank you for reaching out to the Microsoft Q&A Forum. 

I understand that you're having an unexpected issue while attempting to set up calendar synchronization between Microsoft Teams and Google Workspace for your organization's remaining users. The error occurs specifically after the "Match user accounts" step, regardless of which users or how many users you select. I recognize you have already performed extensive troubleshooting, including clearing caches and restarting the process.

Since this synchronization was working for some initial users but is now failing universally for subsequent users, and you have already cleared local caches and restarted the setup, the problem is highly likely related to one of the following:

1. Backend Throttling/Rate Limits: Microsoft or Google may be imposing a rate limit on the number of accounts you can process or synchronize within a certain time window, causing the service request to fail for the remaining bulk of users.
2. Service Connection Status: Although the initial connection setup was successful, the service connection itself (which runs in the background) may be in a temporary failed or degraded state, blocking the final review and finish step.

As a forum moderator, I genuinely wish I could directly delve into the backend systems to diagnose and fix this for you. However, our role here is limited to providing general guidance and solutions that can be applied by users.  

Given the generic "Unexpected error occurred" message, waiting at least 4 to 8 hours before attempting the process again is advisable. This allows any potential backend throttling or temporary service incidents to clear.

If that does not resolve the issue, I recommend that the Global Admin in your organization create a service request with Microsoft Support. A technical support engineer can perform a remote session to investigate the situation, verify the backend configurations, and run any necessary synchronization tools to resolve the problem. If the issue requires further attention, they can escalate it to a specialized team for deeper analysis. Ask The Global Admin in your organization to create a service request with Microsoft support to get advanced technical assistance and diagnostics. For detailed instructions on how to get support, please refer to Get support - Microsoft 365 admin. If you don't know who your IT administrator is, please refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support 

For additional assistance, use this link to find the appropriate contact number: Global Customer Service phone numbers - Microsoft Support 

I truly hope you get your issue resolved swiftly. Please know that even though I can't directly intervene, directing you to the correct, specialized support is the most effective help I can provide from my position. Thank you for your patience and understanding. I'm looking forward to your reply. 

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