tomcat8-instance-create: 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 Debian possible default full paths are:

/usr/bin/tomcat8-instance-create - from package: tomcat8-user

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

Error in other languages:
tomcat8-instance-create: bevel nie gevind nie
tomcat8-instance-create: comandă negăsită
tomcat8-instance-create: comando não encontrado
tomcat8-instance-create: commande introuvable
tomcat8-instance-create: command not found
tomcat8-instance-create: käsku ei ole
tomcat8-instance-create: không tìm thấy lệnh
tomcat8-instance-create: komanda nerasta
tomcat8-instance-create: Kommando nicht gefunden.
tomcat8-instance-create: kommandot finns inte
tomcat8-instance-create: komut yok
tomcat8-instance-create: nie znaleziono polecenia
tomcat8-instance-create: níor aimsíodh an t-ordú
tomcat8-instance-create: no se encontró la orden
tomcat8-instance-create: no s'ha trobat l'ordre
tomcat8-instance-create: opdracht niet gevonden
tomcat8-instance-create: parancs nem található
tomcat8-instance-create: perintah tidak ditemukan
tomcat8-instance-create: príkaz nenájdený
tomcat8-instance-create: příkaz nenalezen
tomcat8-instance-create: команда не найдена
tomcat8-instance-create: командата не е открита
tomcat8-instance-create: 命令找不到
tomcat8-instance-create: コマンドが見つかりません