topic Re: OneLake Data Access (Preview) Issue in Data Engineering

OneLake Data Access (Preview) Issue

lawlesm — Tue, 05 Aug 2025 21:46:22 GMT

We are getting an error when running a Fabric Notebook with PySpark against a Data Lakehouse that has OneLake Data Access preview enabled. We are also schema enabled. The notebook attempts to run a query and it gives us an error that says:

OneSecurity error while invoking OneSecurity API isSystemContextRequired with response error {"code":"InternalError","subCode":0,"message":"An internal error occurred.","timeStamp":"2025-08-05T19:03:34.5458564Z","httpStatusCode":500,"hresult":-2147467259,"details":[{"code":"RootActivityId","message":"1e8211ef-7cda-4e89-9a52-dd9c6246d2be"},{"code":"Param1","message":"OneSecurity default error definition\n\nStatus: 400\nResponse: \n{\r\n \"code\": \"OneSecurityRoleCountLimitExceeded\",\r\n \"subCode\": 0,\r\n \"message\": \"Total role count in the GetRolesMetadata request has exceeded max allowed. Role count in request: 24, max allowed: 20.\",\r\n \"timeStamp\": \"2025-08-05T19:03:34.5209316Z\",\r\n \"httpStatusCode\": 400,\r\n \"hresult\": -2147467259,\r\n \"details\": []\r\n}"}]} and status code: 500 with error code: 500

When we researched this error, it appears there are too many nested groups for the context of the query and it’s resources for OneSecurity to work through. So, we removed several of the groups and even tested with one group on the lakehouse and it still errors and retries ~30 times. Then succeeds? We also tried creating a test user that had no groups, same result (same count of groups [24]. The normal runtime prior to this issue was only a few moments. Now it is hours. This is costing us A LOT of time and money and has impacted production workload. This HAS worked in the past and is only recently an issue since 08/01/2025. Does anyone have experience here with this issue?

Re: OneLake Data Access (Preview) Issue

v-menakakota — Wed, 06 Aug 2025 09:24:34 GMT

Hi @lawlesm ,
Thanks for reaching out to the Microsoft fabric community forum.

Since the notebook is retrying around 30 times before it finally works, it might help to add some basic logging inside your notebook. You can log:

When each query attempt starts and ends
How many times it retries
The error message from each failed attempt

This can help you see if there’s a pattern, like increasing delays.

If I misunderstand your needs or you still have problems on it, please feel free to let us know.  

Best Regards,
Community Support Team

Re: OneLake Data Access (Preview) Issue

lawlesm — Thu, 07 Aug 2025 16:13:25 GMT

We have added logging and nothing looks out of sort besides what I posted above. MS is slow on tickets... So we copied our data out to a new lakehouse without OneLake Data Access enabled and we are back to normal. Something is awry.

Re: OneLake Data Access (Preview) Issue

v-menakakota — Sat, 09 Aug 2025 16:36:43 GMT

Hi @lawlesm ,

Thank you for the update, It’s good that moving the data to a Lakehouse without OneLake Data Access got you back to normal performance, but it definitely confirms something is off with the preview feature.

Even though you’ve found a workaround, I’d still recommend keeping the ticket open with Microsoft so they can investigate and fix the root cause.

Please refer below link on how to raise a contact support or support ticket.
How to create a Fabric and Power BI Support ticket - Power BI | Microsoft Learn

Thank you.

Re: OneLake Data Access (Preview) Issue

v-menakakota — Tue, 12 Aug 2025 10:29:44 GMT

Hi @lawlesm ,

We are following up once again regarding your query. Could you please confirm if the issue has been resolved through the support ticket with Microsoft?

If the issue has been resolved, we kindly request you to share the resolution or key insights here to help others in the community.

Thank you.