Character is missing when encrypt with Rijndael

It's unlikely that someone can help if you don't show the code that you are using. At best one can throw in some guesses:

• You read the file in a string and then you obtain the bytes for encryption you use the wrong text encoding.


• You use CryptoStream class and fail to flush/dispose it properly.


• Encryption actually works fine but you're doing something wrong when decrypting.