sxr-server: 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

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/sxr-server - from package: synopsis

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