After loading the saved pattern and track, I tried to play it but my program got crashed.
Below is my code.

#include “main_app.h”

void SaveFile(TUniSynthMusic music, char path) {
printf(“Save file to: %sn”, path);

FILE *file = fopen(path, "wb");
if (!file) {
    printf("Unable to open file for writing: %sn", path);
    return;
}

// Write the basic TUniSynthMusic structure
fwrite(music, sizeof(TUniSynthMusic), 1, file);

// Write the patterns
for (int i = 0; i < MUSIC_MAX_PATTERNS; i++) {
    fwrite(&music->patterns[i], sizeof(TUniSynthPattern), 1, file);
}

// Write the tracks and their pattern pointers
for (int i = 0; i < MUSIC_MAX_TRACKS; i++) {
    fwrite(&music->tracks[i], sizeof(TUniSynthMusicTrack), 1, file);
    for (int j = 0; j < MUSIC_MAX_PATTERNS_PER_TRACK; j++) {
        if (music->tracks[i].patternPtrs[j] != NULL) {
            int index = music->tracks[i].patternPtrs[j] - music->patterns;
            fwrite(&index, sizeof(int), 1, file);
        } else {
            int index = -1;
            fwrite(&index, sizeof(int), 1, file);
        }
    }
}

fclose(file);

}

void LoadFile(TUniSynthMusic music, char path) {
printf(“Load file from: %sn”, path);

FILE *file = fopen(path, "rb");
if (!file) {
    printf("Unable to open file for reading: %sn", path);
    return;
}

// Read the basic TUniSynthMusic structure
fread(music, sizeof(TUniSynthMusic), 1, file);

// Read the patterns
for (int i = 0; i < MUSIC_MAX_PATTERNS; i++) {
    fread(&music->patterns[i], sizeof(TUniSynthPattern), 1, file);
}

// Read the tracks and their pattern pointers
for (int i = 0; i < MUSIC_MAX_TRACKS; i++) {
    fread(&music->tracks[i], sizeof(TUniSynthMusicTrack), 1, file);
    for (int j = 0; j < MUSIC_MAX_PATTERNS_PER_TRACK; j++) {
        int index;
        fread(&index, sizeof(int), 1, file);
        if (index != -1) {
            music->tracks[i].patternPtrs[j] = &music->patterns[index];
        } else {
            music->tracks[i].patternPtrs[j] = NULL;
        }
    }
}

fclose(file);

}

Any idea or suggestions from the experts.