3509849 - 'couldn't be established' error in SAP Datasphere when using Generic SFTP connection

While setting up the Generic SFTP connection from SAP Datasphere to SFTP server, the following errors appears:

• Connection <SFTP NAME> couldn't be established.
  - Data flows can't be used because of errors in the connection.
  - Replication flows are not supported.
  - Remote tables are not supported.
  Data Flows: Cause: Possible causes of error: Detailed error message (hostkey has been changed for remote host (<SFTP URL>))
  

• Connection <SFTP NAME>  couldn't be established.
  - Data flows can't be used because of errors in the connection.
  - Replication flows are not supported.
  - Remote tables are not supported.
  Data Flows: Cause: Possible causes of error: Detailed error
  message connection is closed by foreign host)
  

SAP Datasphere

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