Error HYT00 in notebook

Hi Pupic,

Thank you for your inquiry on the Microsoft Fabric Community Forum.

Based on my understanding, the behavior is not related to notebook logic, pyodbc configuration, or credentials. The issue appears to be a capacity level SQL endpoint connectivity problem on the affected F8 capacity. The HYT00 error occurs before authentication completes, indicating that the warehouse SQL endpoint is unable to accept new connections within the timeout window due to capacity side resource constraints or transient backend issues. The fact that the Trial capacity works confirms that the problem is isolated to the specific capacity and not to the workload.

Please follow the steps below, which may help resolve the issue:

1. Avoid creating a new ODBC connection in each notebook cell. Use a single connection per run and explicitly close it.
2. Check SQL usage, concurrency, and queue duration in the Capacity Metrics app to confirm whether the capacity is under pressure.
3. Temporarily scale the capacity or move the workspace to a different capacity to confirm that the issue is capacity specific.

Additionally, please refer to the links below:
How to use notebooks - Microsoft Fabric | Microsoft Learn
What Is Data Warehousing in Microsoft Fabric? - Microsoft Fabric | Microsoft Learn
What is the Microsoft Fabric Capacity Metrics app? - Microsoft Fabric | Microsoft Learn
Scale your Fabric capacity - Microsoft Fabric | Microsoft Learn

We hope the information provided helps to resolve the issue. Should you have any further queries, please feel free to contact the Microsoft Fabric Community.

Thank you.