'MD5CryptoServiceProvider' is obsolete: 'Derived cryptographic types are obsolete. Use the Create method on the base type instead.' (https://aka.ms/dotnet-warnings/SYSLIB0021)

'Rfc2898DeriveBytes.Rfc2898DeriveBytes(string, byte[])' is obsolete: 'The default hash algorithm and iteration counts in Rfc2898DeriveBytes constructors are outdated and insecure.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.' (https://aka.ms/dotnet-warnings/SYSLIB0041)

'Rfc2898DeriveBytes.Rfc2898DeriveBytes(string, byte[])' is obsolete: 'The default hash algorithm and iteration counts in Rfc2898DeriveBytes constructors are outdated and insecure.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.' (https://aka.ms/dotnet-warnings/SYSLIB0041)

'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' (https://aka.ms/dotnet-warnings/SYSLIB0022)

'Rfc2898DeriveBytes.Rfc2898DeriveBytes(string, byte[])' is obsolete: 'The default hash algorithm and iteration counts in Rfc2898DeriveBytes constructors are outdated and insecure.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.' (https://aka.ms/dotnet-warnings/SYSLIB0041)

'Rfc2898DeriveBytes.Rfc2898DeriveBytes(string, byte[])' is obsolete: 'The default hash algorithm and iteration counts in Rfc2898DeriveBytes constructors are outdated and insecure.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.' (https://aka.ms/dotnet-warnings/SYSLIB0041)

'RijndaelManaged' is obsolete: 'The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.' (https://aka.ms/dotnet-warnings/SYSLIB0022)

Dereference of a possibly null reference.

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

Cannot convert null literal to non-nullable reference type.

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

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

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

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

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.