There's no way to get documents out of nspire_emu

I know that you know it, but for other readers: it can be done the harder way

One can use a Ndless program that outputs the contents of a file to the serial port under raw or text form, such as:
#include <os.h>

int main(void) {
    FILE * f;
    volatile int c;

    TCT_Local_Control_Interrupts(0xFFFFFFFF);
    f = fopen("/documents/ndless/test.tns","rb");
    if (f) {
        printf("=====\n");
        while ((c = fgetc(f)) != EOF) {
            printf("%02x ", c);
        }
        printf("=====\n");

        fclose(f);
    }

    return 0;
}
within the emulator, and on the host computer, copy&paste the output to whatever piece of code / program that can turn those bytes into a binary. Such as the following trivial code, which I've been using to check the effect of patching well-chosen locations in the document saving code, in order to defeat TI's layers of obfuscation without having to use any decryption code, or having to implement the decompression part of TI's patented XML compression algorithm, on the computer side:
#include <stdio.h>

unsigned char data[] = {
// Paste the output of the program (between the markers) here.
};

int main(void) {
    FILE *f = fopen("test.tns","wb");
    fwrite(data, 1, sizeof(data), f);
    fclose(f);
    return 0;
}

The question:what is the cause for which my files are damaged ?
and if I find this problem in future is there any method to repair my files without losing data ?

Good morning,
 i have an other damaged tns file if any one can repair it he will send me a personal message to give him the password of ziped file because this tns file contain personel informations
 thank you!