I used those steps Redirecting… :
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
echo “deb http://download.mono-project.com/repo/ubuntu xenial main” | sudo tee /etc/apt/sources.list.d/mono-official.list
sudo apt-get update
sudo apt-get install mono-devel
sudo apt-get install mono-complete
sudo apt-get install mono-dbg
sudo apt-get install referenceassemblies-pcl
sudo apt-get install ca-certificates-mono
sudo apt-get install mono-xsp4
After that i fallowing those steps this Download .NET (Linux, macOS, and Windows)
curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.gpg
sudo mv microsoft.gpg /etc/apt/trusted.gpg.d/microsoft.gpg
“17.04”
sudo sh -c ‘echo “deb [arch=amd64] Index of /repos/microsoft-ubuntu-zesty-prod/ zesty main” > /etc/apt/sources.list.d/dotnetdev.list’
sudo apt-get update
" sudo apt-get install dotnet-sdk-2.0.0 " (at this the problem show)
{
}