error ftp_nb_fput

Hello – I can’t figure out what is going wrong when attempting to backup my site via FTP. I have logged in successfully but receive the following error message:

* PHP event: code E-WARNING: ftp_nb_fput(): can’t open that file: no such directory (line 93, wp-content/plugins/updraftplus/includes/ftp.class.php)

I did in fact locate the file however I did not investigate line 93 because I don’t know how to fix.

Please help.