Microsoft.CSharp.targets: 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/mono/xbuild/12.0/bin/Microsoft.CSharp.targets - from package: mono-xbuild

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

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