RESOLUTION
Make sure that you are within httpdocs, httpsdocs, or cgi-bin directories. It is not possible to upload files into the domain's root directory. Also check permissions/ownership for these directories. It should be as follows:
# ls -ald anon_ftp cgi-bin httpdocs httpsdocs private
drwxr-x--- 5 psam psaserv 4096 Jul 1 10:26 anon_ftp
drwxr-x--- 2 psam psaserv 4096 Jul 1 10:26 cgi-bin
drwxr-x--- 5 psam psaserv 4096 Jul 1 11:17 httpdocs
drwxr-x--- 3 psam psaserv 4096 Jul 1 10:26 httpsdocs
drwx------ 2 psam root 4096 Jul 1 10:26 private