One or more crypto algorithms such as TripleDESCryptoServiceProvider, DESCryptoServiceProvider, and RC2CryptoServiceProvider are being used by your application. These algorithms are marked as obsolete and are no longer recommended. Please consider switching to a more modern and robust algorithm instead. Please check out the reference for some recommended algorithms.
var des = new DESCryptoServiceProvider();
using (var aes = Aes.Create())
{
//
}