Forum Discussion
Transport-level error when refreshing Excel Power Queries
We are encountering a transport-level error when refreshing data in Excel. It seems that the random users have an issue with random reports but at the same time another user can successfully refresh the report.
It appears that Excel only successfully refreshes data when all queries are loaded to the worksheet. If a query is marked as "Connection Only" and is used as a dependency for other queries, the refresh process may break, resulting in a transport-level error.
Has anyone else experienced this? Are there known fixes or best practices to ensure reliable refreshes while keeping queries as "Connection Only"?
2 Replies
Thank you so much for your answer. After updating all setting the report has started generating another error
From what you’ve described:
- Errors are intermittent — some users/reports fail while others work.
- Behavior differs if queries are loaded to worksheet vs. connection only.
- This points less to SQL Server itself, and more to how Excel’s Power Query engine is managing connections.
Power Query creates multiple connections in parallel when refreshing, especially when you use “Connection Only” queries feeding into dependent queries.
Some environments (firewalls, load balancers, SQL TCP keepalives, VPNs, or Excel’s own engine limits) can cause those connections to get dropped.What you can do…
Force Power Query to serialize refreshes
By default, Excel may refresh multiple queries in parallel. To stop race conditions:
- In Excel:
Data → Get Data → Query Options → Data Load → Background Data → Disable "Allow data preview to download in the background" - Also:
Data → Connections → Properties → Enable "Refresh this connection on its own" and disable background refresh.
This forces Excel to keep connections more stable.
Additional…
Avoid unnecessary “Connection Only” dependencies
Check SQL Server settings (Check Timeout)
Check Excel client stability (Ensure all users are on the same build of Excel)
My answers are voluntary and without guarantee!
Hope this will help you.
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