Padding is Invalid

[PIN0L33KZ]

Hi, if i decrypt any String i get this Exception thrown.
System.Security.Cryptography.CryptographicException: "Padding is invalid and cannot be removed."

This is the Code Used:

        'Encrypt Password
        Dim encrypter = New EasyEncrypt
        _encrypted_passwd = encrypter.Encrypt("TestString", Encoding.Default)
        Console.WriteLine(_encrypted_passwd)

        'Decrypt Password
        Dim decrypter = New EasyEncrypt
        _decrypted_passwd = decrypter.Decrypt(_encrypted_passwd, Encoding.Default) 'Excepton is thrown
        Console.WriteLine(_decrypted_passwd)