I receive this kind of error when I leave the ftp connection alone and the server terminates the connection.
Environment:
Linux server running ftp client vsftpd. Timeout set to 15min. This is managed by the service provider, they don't want to change this setting.
When I leave NP++ open more than 15 min - or worse - the file editing takes more than 15 min -, the upload or download attempt fails and NP++ becomes freezed. Note that this also happens when I try to open a dir in the folder structure
This annoying proplem can be solved with a background send-receive of some ftp commands just to keep alive the connection.
Currently I solve the problem by disconnecting-reconnecting, but this is also annoying since the opened dir. structure resets to a completely collapsed state...
This problem is not present on every computer. It may be a hardware problem or a software installed. I have 2 computers, both running Windows 7 x64. On one computer nppftp freezes after timeout, on the another not.