Invalid length for a Base-64 char array

Error "Invalid length for a Base-64 char array" when using Convert. FromBase64String(InputString)

Resolution:

When Crypted, replace "+" to space.

string encryptString = Convert.ToBase64String(ms.ToArray());

encryptString = encryptString.Replace("+", " ");

 

When decrypted, replace space back to "+"

encryptString = encryptString.Replace(" ", "+");