mstmwrite: command not found

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 CentOS possible default full paths are:

/usr/bin/mstmwrite - from package: mstflint

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/mstmwrite - from package: mstflint

You may install the required package with command apt-get install {package}

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