While passing apostrophe in company name "company's" is giving error

Invalid length for a Base-64 char array or string.

public  string Decrypt(string dataToDecrypt)
       {

           byte[] data = Convert.FromBase64String(dataToDecrypt.Replace(' ', '+'));
           string decryptedData = string.Empty;

           try
           {
               //ReDim Preserve data(DataLen - 1)

               // The key and initialization vector : change them for your application
               byte[] _key = {
           132,
           42,
           53,
           124,
           75,
           56,
           87,
           38,
           9,
           10,
           161,
           132,
           183,
           91,
           105,
           16,
           117,
           218,
           149,
           230,
           221,
           212,
           235,
           64
       };
               byte[] _iv = {
           83,
           71,
           26,
           58,
           54,
           35,
           22,
           11,
           83,
           71,
           26,
           58,
           54,
           35,
           22,
           11
       };

               MemoryStream mStream = new MemoryStream(data, 0, data.Length);
               // instead of writing the decrypted text

               RijndaelManaged aes = new RijndaelManaged();

               CryptoStream cs = new CryptoStream(mStream, aes.CreateDecryptor(_key, _iv), CryptoStreamMode.Read);

               StreamReader sr = new StreamReader(cs);
               ASCIIEncoding ut = new ASCIIEncoding();
               string ab = sr.ReadToEnd();
               //UTF8Encoding
               decryptedData = ab;
               return ab;
           }
           catch (Exception ex)
           {
               throw ex;
           }
       }

byte[] data = Convert.FromBase64String(dataToDecrypt);