Assuming that you are attempting to manually update the software on the OpenStage phone, here is a common FAIL scenario:
When you setup your FTP server, you are required to configure the FTP server's "path". For example, the FTP server's path may be: c:\FTP_path
When you configure the "File Transfer" settings in the OpenStage phone's Web-Based Management, one of the required fields is "FTP Path".
This field represents the same information that you have already entered into the FTP server.
Typically the first reaction is to enter: c:\FTP_path
But this double-entry confuses the device attempting to locate the specific filename at this FTP Path.
To eliminate this confusion, try using a "/" or "." in the OpenStage phone's Web-Based Management "FTP Path" field.
This special character advises the phone that the FTP Path is specified inside the FTP Server.
Good Luck!