Free Pascal Compiler - Stream read error

Project crypt hat Exception-Klasse "EReadError" ausgelöst mit der Meldung:
Stream read error
Bei Adresse 410EE5

Program crypt;
{$mode objfpc}{$H+}

uses
  Classes, Crt, SysUtils, BlowFish;

const TheFile: String = 'CryptFile.txt';  

var
  EncodeBlowFishStream: TBlowFishEncryptStream;
  DecodeBlowFishStream: TBlowFishDeCryptStream;
  EncodeStringStream,DeCodeStringStream: TStringStream;
  EncodeString,DecodedString,key,value: String;
  Choice: Char;

Procedure Encrypt;
Begin
     EncodeStringStream := TStringStream.Create('');  
     EncodeBlowFishStream := TBlowFishEncryptStream.Create(key,EncodeStringStream);
     EncodeBlowFishStream.WriteAnsiString(value);
     EncodeString := EncodeStringStream.DataString;
     EncodeBlowFishStream.Free;
     EncodeStringStream.Free;
End;

Procedure Decrypt;
Begin
     DeCodeStringStream := TStringStream.Create(value);
     DecodeBlowFishStream := TBlowFishDeCryptStream.Create(key,DeCodeStringStream);
     DecodedString := DecodeBlowFishStream.ReadAnsiString;
     DecodeBlowFishStream.Free;
     DeCodeStringStream.Free;
End;

Function ReadFile(File2Read:String):String;
Var  String2Read: TstringList;
Begin
     Value:='';  
     String2Read := TStringList.Create;
     Try
        String2Read.LoadFromFile(File2Read);
        value:=String2Read;
     Finally
         String2Read.Free;
     End;
End;

Function WriteFile(File2Write:String):String;
Var String2Write: TStringList;
Begin
     String2Write := TStringList.Create;
     Try
        String2Write.Add(EncodeString);
        String2Write.SaveToFile(File2Write);
     Finally
        String2Write.Free;
        EncodeString:='';  
     End;
End;

Begin
  While True Do
  Begin
     ClrScr;
     TextColor(LightGreen);
     Write('Encrypt = 1 | Decrypt = 2 | Exit = 3 ... Your choice: ');  
     Choice := ReadKey;
     WriteLn;
     If Choice='3' Then  
        Halt(0);

     Write('Key: ');  
     ReadLn(key);

     Case Choice of
      '1': Begin  
                Write('Text: ');  
                ReadLn(value);
                Encrypt;
                WriteLn('Encrypted: ' + EncodeString);  
                WriteLn('Decrypted: ' + value);  
                WriteFile(TheFile);
           End;
      '2': Begin  
                ReadFile(TheFile);
                Decrypt;
                WriteLn('Encrypted: ' + value);  
                writeLn('Decrypted: ' + DecodedString);  
           End;

     End; //Case
     WriteLn;
     TextColor(white);
     Write('Press ENTER to continue...');  
     ReadLn;
  End; //While
End.