It's obvious you are using FileZilla (the client, that is). My statement was for FileZilla Server. So *if* you also use FileZilla Server as FTP server you can enable the ''Allow downloading of files which are open for writing by another process'' option in the settings.
The file you want to download is open by another process on the server. For this reason, the FTP server process cannot open the file for reading. This mostly happens on Windows in all its glory. You can use a tool like Unlocker (Windows) to check which process locks the file handle.
The file you want to download is open by another process on the server. For this reason, the FTP server process cannot open the file for reading. This mostly happens on Windows in all its glory. You can use a tool like Unlocker (Windows) to check which process locks the file handle.