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High severitydata source

Power BI Refresh Error:
FtpFailedToConnectToFtpServer

What does this error mean?

ADF or Fabric could not connect to the FTP server. Most common cause: using the SFTP connection type instead of FTP, or port 21 being blocked.

Common causes

  • 1An incorrect Connection type is used — for example, using the SFTP (Secure FTP) connection type to connect to a plain FTP server
  • 2The FTP server port is wrong — FTP uses port 21 by default

How to fix it

  1. 1Verify you are using the FTP connection type in your linked service, not SFTP.
  2. 2Check the port of the target server — FTP uses port 21 by default.
  3. 3If the server requires passive mode data transfer, ensure the firewall allows ports 1024–65535 from the integration runtime IP.

Frequently asked questions

Does this error affect multiple datasets at once?

If multiple datasets connect to the same data source, yes — all of them will fail until the source connectivity is restored.

Can this error be caused by a server migration or rename?

Yes — if the server name, database name, or connection string changed (e.g., during a cloud migration), Power BI still holds the old connection details. Update the connection in Power BI Desktop and republish.

Does this error appear in Power BI Desktop?

Sometimes — if you open the .pbix file and attempt a refresh, Desktop will surface the same connection error. This is useful for debugging without affecting the Service dataset.

Will the error resolve automatically once the source is back online?

Only if it was a temporary outage. The next scheduled refresh will succeed automatically. If the connection string changed or credentials expired, manual intervention is needed.

Source · learn.microsoft.com/en-us/fabric/data-factory/connector-troubleshoot-ftp-sftp-http

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