Session ID errors in Excel with Query Scale-Out enabled

[nicg]

The session ID error is normally encountered when a connection from Excel to a Power BI model (Analyze in Excel feature) has timed-out. Usually, a second refresh resolves the issue.

However, when Query Scale-Out is enabled on a large model in our P3 capacity, some users receive the message repeatedly for long periods of time. They are unable to use their reports during this time. Turning off Scale-Out resolves the issue.

The error message is:

"The '<eupi>XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX</eupi>' session ID cannot be found. Either the session does not exist or it has already expired."

I'm assuming this has something to do with the auto-generated replicas being dropped or changing ID and Excel can no longer find it, but don't know that for a fact. Power BI reports do not seem to have this issue.

[v-xiaoyan-msft]

Hi @nicg ,

From the information available, it seems that turning off Query Scale-Out resolves the issue, which suggests that the problem might be related to the auto-generated replicas being dropped or changing IDs, causing Excel to lose track of them. This issue doesn't seem to affect Power BI reports, which might indicate a specific problem with how Excel handles these sessions.

this issue is complex which may need to collect log files for further troubleshooting. Since community support engineers don't have that access, I would suggest opening a Support Ticket. If you are a Power BI Pro or Fabric licensee, you can create a support ticket for free and a dedicated Microsoft engineer will come to solve the problem for you. 
It would be great if you continue to share in this issue to help others with similar problems after you know the root cause or solution.

The link of Power BI Support: Support | Microsoft Power BI

For how to create a support ticket, please refer to How to create a support ticket in Power BI - Microsoft Power BI Community

Best Regards,
Community Support Team _ Caitlyn