Mono.Cecil.Pdb.dll: 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/lib/monodevelop/bin/Mono.Cecil.Pdb.dll - from package: monodevelop

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

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