The "--output" option isn't supported when building a solution. Specifying a solution-level output path results in all projects copying outputs to the same directory, which can lead to inconsistent builds.

'MD5CryptoServiceProvider' is obsolete: 'Derived cryptographic types are obsolete. Use the Create method on the base type instead.'

'Rfc2898DeriveBytes.Rfc2898DeriveBytes(string, byte[])' is obsolete: 'The default hash algorithm and iteration counts in Rfc2898DeriveBytes constructors are outdated and insecure. Use a constructor that accepts the hash algorithm and the number of iterations.'

'Rfc2898DeriveBytes.Rfc2898DeriveBytes(string, byte[])' is obsolete: 'The default hash algorithm and iteration counts in Rfc2898DeriveBytes constructors are outdated and insecure. Use a constructor that accepts the hash algorithm and the number of iterations.'

'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.'

'Rfc2898DeriveBytes.Rfc2898DeriveBytes(string, byte[])' is obsolete: 'The default hash algorithm and iteration counts in Rfc2898DeriveBytes constructors are outdated and insecure. Use a constructor that accepts the hash algorithm and the number of iterations.'

'Rfc2898DeriveBytes.Rfc2898DeriveBytes(string, byte[])' is obsolete: 'The default hash algorithm and iteration counts in Rfc2898DeriveBytes constructors are outdated and insecure. Use a constructor that accepts the hash algorithm and the number of iterations.'

'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.'

Non-nullable field '_backup' must contain a non-null value when exiting constructor. Consider declaring the field as nullable.