slapschema: 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/sbin/slapschema - from package: openldap-servers

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

On Debian possible default full paths are:

/usr/sbin/slapschema - from package: slapd

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

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