Symptoms

SFTP connection times out randomly with error message "Connection closed by Remote Host" after the code upgrade.Unable to put any files into Unity user home directory.

Cause

1. When the SFTP connections are disconnected from the Unity side, the Unity side reported force close of SFTP sessions on the NAS server.2. From the logs, there is evidence of another DR NAS server doing replication refresh which seemed to force reloading of SFTP config on that DR NAS server.

Resolution

Upgrade the Unity software code version to Unity OE 5.1 or later which has the fix for this issue.

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