Fabric Notebook Spark Session Error

Hi dragonlobster ,

Thank you for reaching out. We understand the urgency of your situation and appreciate your patience while we investigate this issue.

Based on the error message you provided, it appears that the notebook session is failing due to an internal service error.

Error: [NoAvailableCoreService] An internal error occurred. HTTP status code: 500.
We have observed similar reports from other users experiencing notebook session failures, where notebooks either fail to start or remain stuck in a loading state.

A similar issue was identified as a server-side problem, and affected users reported that it was resolved within a day without any changes from their end.
Solved: Fabric issue: notebooks keep loading when creating... - Microsoft Fabric Community

As this is likely a temporary backend issue, we recommend retrying after some time. Restarting the Fabric capacity or using a different browser may help. However, if the issue persists, please raise a support ticket with Microsoft for further investigation.
Please follow these links to create a support ticket.
How to create a Fabric and Power BI Support ticket - Power BI | Microsoft Learn
Microsoft Fabric Support and Status | Microsoft Fabric

Hope this helps. Please reach out for further assistance.

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly and a kudos would be appreciated.

Best Regards,
Vinay.