The variable 'ex' is declared but never used

Possible null reference argument for parameter 'path' in 'DirectoryInfo Directory.CreateDirectory(string path)'.

Converting null literal or possible null value to non-nullable type.

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

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

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

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

Non-nullable property 'FileMd5' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

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

'MD5CryptoServiceProvider' is obsolete: 'Derived cryptographic types are obsolete.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

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

The type name 'pack' only contains lower-cased ascii characters. Such names may become reserved for the language.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.