rpsblast+: 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
/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/rpsblast+ - from package: ncbi-blast+

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