Problem:

After installation on Gentoo Linux vsftp server connection fails with error:

Antwort:    500 OOPS: cannot locate user entry:ftpsecure
Fehler:    Kritischer Fehler: Herstellen der Verbindung zum Server fehlgeschlagen
Filezilla reports: cannot locate user entry:ftpsecure
Error: Critical Error: Connection to the server failed

Looks like installation routines don't deliver all modifications. You need oto execute the following command

useradd -g ftpsecure -s /sbin/nologin ftpsecure

this adds the reqired ftpsecure user which can't login.

Hint: this is a result if you request that user by modification of the vsftpd.conf - file with line:

nopriv_user=ftpsecure