gss_clnt_send_err: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/sbin/gss_clnt_send_err - from package: nfs-common

You may install the required package with command apt-get install {package}
Error in other languages:
gss_clnt_send_err: bevel nie gevind nie
gss_clnt_send_err: comandă negăsită
gss_clnt_send_err: comando não encontrado
gss_clnt_send_err: commande introuvable
gss_clnt_send_err: command not found
gss_clnt_send_err: käsku ei ole
gss_clnt_send_err: không tìm thấy lệnh
gss_clnt_send_err: komanda nerasta
gss_clnt_send_err: Kommando nicht gefunden.
gss_clnt_send_err: kommandot finns inte
gss_clnt_send_err: komut yok
gss_clnt_send_err: nie znaleziono polecenia
gss_clnt_send_err: níor aimsíodh an t-ordú
gss_clnt_send_err: no se encontró la orden
gss_clnt_send_err: no s'ha trobat l'ordre
gss_clnt_send_err: opdracht niet gevonden
gss_clnt_send_err: parancs nem található
gss_clnt_send_err: perintah tidak ditemukan
gss_clnt_send_err: príkaz nenájdený
gss_clnt_send_err: příkaz nenalezen
gss_clnt_send_err: команда не найдена
gss_clnt_send_err: командата не е открита
gss_clnt_send_err: 命令找不到
gss_clnt_send_err: コマンドが見つかりません