Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

Calling all Data Engineers! Fabric Data Engineer (Exam DP-700) live sessions are back! Starting October 16th. Sign up.

Reply
Padmaja_UH
New Member

dataflow fails on writetodestination step with this error - details below

999999 Couldn't refresh the entity because of an issue with the mashup document MashupException.Error: Microsoft SQL: A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: TCP Provider, error: 0 - The semaphore timeout period has expired.) Details: Reason = DataSource.Error;DataSourceKind = Lakehouse;DataSourcePath = Lakehouse;Message = A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: TCP Provider, error: 0 - The semaphore timeout period has expired.);ErrorCode = -2146232060;Number = 121;Class = 20;State = 0;Microsoft.Data.Mashup.Error.Context = User GatewayObjectId: 0b462d6e-96ea-4a93-813f-f1af6066bdb0

1 REPLY 1
lbendlin
Super User
Super User

Ask the owners of the SQL Server data soure if they are enforcing a timeout setting on their side.

Helpful resources

Announcements
FabCon Global Hackathon Carousel

FabCon Global Hackathon

Join the Fabric FabCon Global Hackathon—running virtually through Nov 3. Open to all skill levels. $10,000 in prizes!

September Power BI Update Carousel

Power BI Monthly Update - September 2025

Check out the September 2025 Power BI update to learn about new features.

FabCon Atlanta 2026 carousel

FabCon Atlanta 2026

Join us at FabCon Atlanta, March 16-20, for the ultimate Fabric, Power BI, AI and SQL community-led event. Save $200 with code FABCOMM.

Top Solution Authors
Top Kudoed Authors