topic Re: Notebook new Standard or HC sessions won't start. This current seems to ocurre random in Data Engineering

Notebook new Standard or HC sessions won't start. This current seems to ocurre random

ArjanFraaij — Mon, 11 Aug 2025 08:41:11 GMT

Hi,

Current wen starting note book sessions in a Fabric Workspace we get a messages like "Your compute session was disconnected."

This seems to have started last week after a little while all seem to work again and then starts failing again during the day.

It shows a Diagnostic information like: (Removed parts of shown key's

Diagnostic ID: 6f354ca5-3b33-4a62-b2e2-be7a9bdfcfe0

Timestamp: 2025-08-11T08:26:59.500Z

Message: [object CloseEvent]

JSON
{
"type": "close",
"timeStamp": 105513.20000000019,
"code": 1000,
"reason": "{\"reason\":\"Session error or stopped.\",\"state\":\"session-completed\"}",
"wasClean": true,
"target": {
"url": "wss://d9ada.pbidedicated.windows.net/webapi/capacities/D906ADA/workloads/Notebook/Data/Direct/api/workspaces/f4b104595/artifacts/de98e77fb980a0/jupyterApi/versions/1/api/kernels/c062a13b1e5/channels?token=dummy_token&session_id=eb9a5ead-e2ed",
"readyState": 3,
"protocolsProfile": [
7,
4608
]
},
"currentTarget": {
"url": "wss://d9044796ada.pbidedicated.windows.net/webapi/capacities/D90447C076ADA/workloads/Notebook/Data/Direct/api/workspaces/f4b404595/artifacts/de98e77f-43pi/versions/1/api/kernels/c062a148-0b9613b1e5/channels?token=dummy_token&session_id=eb9a5eed",
"readyState": 3,
"protocolsProfile": [
7,
4608
]
},
"isTrusted": true
}

Additional info: InstanceId: f7d170-9a8ce89b40f7

Re: Notebook new Standard or HC sessions won't start. This current seems to ocurre random

wardy912 — Mon, 11 Aug 2025 10:11:45 GMT

Hi @ArjanFraaij

What SKU Fabric capacity are you using? Sounds like you may want to increase it.

If you're using an F2 for example, you won't be able to run multiple spark sessions at the same time.

Re: Notebook new Standard or HC sessions won't start. This current seems to ocurre random

ArjanFraaij — Mon, 11 Aug 2025 10:50:34 GMT

We ar running F64 and capacity is not yet on his max on these times

Re: Notebook new Standard or HC sessions won't start. This current seems to ocurre random

wardy912 — Mon, 11 Aug 2025 10:54:07 GMT

Ah, F64 is plenty so capacity is unlikely.

Unfortunately, I can't offer any better advice than to raise a ticket with Microsoft.

Re: Notebook new Standard or HC sessions won't start. This current seems to ocurre random

v-dineshya — Mon, 11 Aug 2025 12:18:06 GMT

Hi @ArjanFraaij ,

Thank you for reaching out to the Microsoft Community Forum.

Please check below things to fix the issue.

1. Restart the notebook kernel and re-run the cell. Try running the same notebook in a new session or workspace. Switch to High Concurrency sessions instead of Standard ones.

2. Increase timeout in Workspace Settings. Workspace Settings --> Data Engineering --> Spark Settings --> Jobs.

3. Clear browser cache and cookies. Use Microsoft Edge for best compatibility. Disable extensions that may block WebSocket connections.

4. Check with your admin to review the Spark job logs in the Fabric Admin portal and Capacity metrics at the time of failure.

Please refer below community threads.

Solved: Fabric Notebook disconnects when running a certain... - Microsoft Fabric Community

Solved: Session Startup Issue on Fabric for the Past 5 Day... - Microsoft Fabric Community

Solved: Re: Fabric Notebook Session Is Not Getting Created... - Microsoft Fabric Community

Solved: Re: Notebook Status - Stopped (Session Timed Out) - Microsoft Fabric Community

Solved: Notebook Session Issue - Microsoft Fabric Community

I hope this information helps. Please do let us know if you have any further queries.

Regards,

Dinesh

Re: Notebook new Standard or HC sessions won't start. This current seems to ocurre random

v-dineshya — Thu, 14 Aug 2025 17:10:32 GMT

Hi @ArjanFraaij ,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. And, if you have any further query do let us know.

Regards,

Dinesh

Re: Notebook new Standard or HC sessions won't start. This current seems to ocurre random

v-dineshya — Mon, 18 Aug 2025 05:48:53 GMT

Hi @ArjanFraaij ,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. And, if you have any further query do let us know.

Regards,

Dinesh

Re: Notebook new Standard or HC sessions won't start. This current seems to ocurre random

ArjanFraaij — Mon, 18 Aug 2025 13:55:50 GMT

The base issue of sessions that won't start seems to be gone today

Re: Notebook new Standard or HC sessions won't start. This current seems to ocurre random

v-dineshya — Tue, 19 Aug 2025 06:29:53 GMT

Hi @ArjanFraaij ,

If the issue still persists, As mentioned by @wardy912 in his previous response. Please raise a support ticket. I recommend opening a Microsoft support ticket so they can trace the issue.

To raise a support ticket for Fabric and Power BI, kindly follow the steps outlined in the following guide:

How to create a Fabric and Power BI Support ticket - Power BI | Microsoft Learn

Regards,

Dinesh

Re: Notebook new Standard or HC sessions won't start. This current seems to ocurre random

v-dineshya — Fri, 22 Aug 2025 16:30:57 GMT

Hi @ArjanFraaij ,

We are following up to inquire whether you have raised the support ticket. If you have already done so, we kindly request you to share your feedback regarding the issue raised.In case a solution has been provided, we would be grateful if you could share it with the community. This will assist others facing similar challenges and benefit the wider community. If you need any more assistance, please feel free to connect with the Microsoft Fabric community.

Regards,

Dinesh