FTP/sFTP problem

As of the upgrade to 16.04 LTS I have been unable to use FTP or
sFTP to put files on the server. FileZilla works without error
but trying sFTP manually always get the error 550 Permission
denied no matter what directory I chose or what the permissions
are of the directory tree.

I am suspecting it is a error in configuration that does not
allow uploads.

I checked GOOGLE, but found nothing helpful except a suggestion
to look at ftp.conf or vsftp.conf, neither of which I could find
in /etc.

suggestions ?