Bad data exception in decryption

public string EncryptTripleDES(string PlainText, string key)
        {
            ICryptoTransform encryptor = PCIDSS.CreateDES(key).CreateEncryptor();
            byte[] bytes = Encoding.Unicode.GetBytes(PlainText);
            return Convert.ToBase64String(encryptor.TransformFinalBlock(bytes, 0, bytes.Length));
            
        } 

public string DecryptTripleDES(string CypherText, string key)
        {

            byte[] inputBuffer = Convert.FromBase64String(CypherText);
            return Encoding.Unicode.GetString(PCIDSS.CreateDES(key).CreateDecryptor().TransformFinalBlock(inputBuffer, 0, inputBuffer.Length));

        }