FTP Error: ftp_nb_fput(): php_connect_nonb() failed

That mostly happens, if Ports to the FTP Server not opened correctly. Please check your FTP Server installation.

To elaborate the error:
Connection onto the ftp-server is established, the directory for the Website name is written, but there’s nothing written into it.

The Server installation is listening to port 21 forwarded via a non-standard port.
Does FTP-over-SSL need another port to communicate back that has to be forwarded?

I double-checked with a Fritz!NAS – ports can’t be changed there, and the connection worked until the Update of both FritzOS and BackWPup.

FTP connection onto the Fritz Thing works after the FritzOS update as far I can see (double-checked with another service writing ftp backups).

So I have at least one FTP instance that seems to work and still BackWPup Plugin not working (anymore).

Thanks for any help.

L.B.Q.R.

I have tested it again with my Fritz!Box. And it works.
You must activate Passive transfer. The Fritz!Box option that only allows ssl connection don’t work.
Fritz OS 6.03