abo: 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/share/solr/bin/abo - from package: solr-common

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

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