skkdic-expr: 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
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

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/bin/skkdic-expr - from package: skktools

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