diff --git a/.gitignore b/.gitignore
index 8987337..d5b5272 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,8 @@
 /BLOG.MD
 /__pycache__
 /archive
-/downloads
+/downloads/*
 /headers.json
 /renderer.js
-/ttf_character_mapping.json
\ No newline at end of file
+/ttf_character_mapping.json
+/decoded_book.epub
\ No newline at end of file
diff --git a/decoded_book.epub b/decoded_book.epub
deleted file mode 100644
index 5367200..0000000
Binary files a/decoded_book.epub and /dev/null differ
diff --git a/download_full_book.py b/download_full_book.py
index 719b1a6..77913cc 100755
--- a/download_full_book.py
+++ b/download_full_book.py
@@ -23,19 +23,63 @@ def main():
     asin = sys.argv[1]
     auto_confirm = '--yes' in sys.argv or '-y' in sys.argv
     output_base = Path(f'downloads/{asin}')
-    output_base.mkdir(parents=True, exist_ok=True)
+
+    # Ensure output directory exists
+    try:
+        output_base.mkdir(parents=True, exist_ok=True)
+        print(f"[✓] Output directory ready: {output_base}/")
+    except Exception as e:
+        print(f"[✗] ERROR: Cannot create output directory {output_base}: {e}")
+        sys.exit(1)
 
     # Load credentials
     headers_file = Path('headers.json')
     if not headers_file.exists():
-        print("[✗] headers.json not found!")
+        print("[✗] ERROR: headers.json not found!")
+        print("\nCreate headers.json in the current directory with:")
+        print('  {')
+        print('    "headers": {"x-adp-session-token": "..."},')
+        print('    "cookies": "session-id=...; ..."')
+        print('  }')
         sys.exit(1)
 
-    with open(headers_file) as f:
-        headers_data = json.load(f)
+    try:
+        with open(headers_file) as f:
+            headers_data = json.load(f)
+    except json.JSONDecodeError as e:
+        print(f"[✗] ERROR: Invalid JSON in headers.json: {e}")
+        print("\nEnsure headers.json is valid JSON format")
+        sys.exit(1)
+    except Exception as e:
+        print(f"[✗] ERROR: Cannot read headers.json: {e}")
+        sys.exit(1)
+
+    # Validate headers structure
+    if not isinstance(headers_data, dict):
+        print("[✗] ERROR: headers.json must contain a JSON object")
+        sys.exit(1)
 
     cookies = headers_data.get('cookies', '')
-    adp_token = headers_data['headers'].get('x-adp-session-token') if 'headers' in headers_data else None
+    if not cookies:
+        print("[✗] ERROR: No 'cookies' field found in headers.json!")
+        print("\nEnsure headers.json contains:")
+        print('  {')
+        print('    "cookies": "session-id=...; ..."')
+        print('  }')
+        sys.exit(1)
+
+    if not cookies.strip():
+        print("[✗] ERROR: 'cookies' field is empty in headers.json!")
+        sys.exit(1)
+
+    adp_token = None
+    if 'headers' in headers_data:
+        if not isinstance(headers_data['headers'], dict):
+            print("[⚠] WARNING: 'headers' field is not a JSON object, ignoring")
+        else:
+            adp_token = headers_data['headers'].get('x-adp-session-token')
+            if not adp_token:
+                print("[⚠] WARNING: No 'x-adp-session-token' found in headers")
 
     # Initialize downloader (single session for entire book)
     print(f"\n{'='*80}")
@@ -46,7 +90,15 @@ def main():
 
     # Get book metadata
     print("[*] Getting book metadata...")
-    metadata = downloader.start_reading(asin)
+    try:
+        metadata = downloader.start_reading(asin)
+    except Exception as e:
+        print(f"[✗] ERROR: Failed to get book metadata: {e}")
+        print("\nPossible issues:")
+        print("  - Invalid ASIN")
+        print("  - Invalid or expired credentials in headers.json")
+        print("  - Network connection problem")
+        sys.exit(1)
 
     title = metadata.get('deliveredAsin', asin)
     revision = metadata.get('contentVersion', '')
@@ -70,22 +122,48 @@ def main():
 
     # Download from position 0 to get the complete book including front matter
     print(f"\n[*] Batch 0: position 0...")
-    first_tar = downloader.render_pages(asin, revision, start_position=0, num_pages=5)
-    first_files = downloader.extract_tar(first_tar, output_base / 'batch_0')
+    try:
+        first_tar = downloader.render_pages(asin, revision, start_position=0, num_pages=5)
+        batch_0_dir = output_base / 'batch_0'
+        batch_0_dir.mkdir(parents=True, exist_ok=True)
+        first_files = downloader.extract_tar(first_tar, batch_0_dir)
+    except Exception as e:
+        print(f"[✗] ERROR: Failed to download batch 0: {e}")
+        sys.exit(1)
 
     # Get position range from batch 0
-    page_data_file = list((output_base / 'batch_0').glob('page_data_*.json'))[0]
-    with open(page_data_file) as f:
-        first_pages = json.load(f)
+    try:
+        page_data_files = list((output_base / 'batch_0').glob('page_data_*.json'))
+        if not page_data_files:
+            print("[✗] ERROR: No page_data_*.json found in batch 0")
+            sys.exit(1)
+        page_data_file = page_data_files[0]
+        with open(page_data_file) as f:
+            first_pages = json.load(f)
 
-    batch_0_start = first_pages[0]['startPositionId']
-    batch_0_end = first_pages[-1]['endPositionId']
-    print(f"[✓] Batch 0: {batch_0_start} to {batch_0_end} ({len(first_files)} files)")
+        if not first_pages:
+            print("[✗] ERROR: No pages found in batch 0")
+            sys.exit(1)
+
+        batch_0_start = first_pages[0]['startPositionId']
+        batch_0_end = first_pages[-1]['endPositionId']
+        print(f"[✓] Batch 0: {batch_0_start} to {batch_0_end} ({len(first_files)} files)")
+    except Exception as e:
+        print(f"[✗] ERROR: Failed to parse batch 0 data: {e}")
+        sys.exit(1)
 
     # Load TOC to estimate book length
     toc_file = output_base / 'batch_0' / 'toc.json'
-    with open(toc_file) as f:
-        toc = json.load(f)
+    if not toc_file.exists():
+        print("[✗] ERROR: toc.json not found in batch 0")
+        sys.exit(1)
+
+    try:
+        with open(toc_file) as f:
+            toc = json.load(f)
+    except Exception as e:
+        print(f"[✗] ERROR: Failed to parse toc.json: {e}")
+        sys.exit(1)
 
     last_toc_pos = max(entry['tocPositionId'] for entry in toc)
     print(f"[*] Book ends around position {last_toc_pos}")
@@ -116,10 +194,19 @@ def main():
         try:
             print(f"\n[*] Batch {batch_num}: position {current_pos}...")
             tar_data = downloader.render_pages(asin, revision, start_position=current_pos, num_pages=5)
-            files = downloader.extract_tar(tar_data, output_base / f'batch_{batch_num}')
+
+            # Ensure batch directory exists
+            batch_dir = output_base / f'batch_{batch_num}'
+            batch_dir.mkdir(parents=True, exist_ok=True)
+            files = downloader.extract_tar(tar_data, batch_dir)
 
             # Get end position from this batch
-            page_file = list((output_base / f'batch_{batch_num}').glob('page_data_*.json'))[0]
+            page_files = list(batch_dir.glob('page_data_*.json'))
+            if not page_files:
+                print(f"[!] Batch {batch_num}: No page data found, stopping")
+                break
+
+            page_file = page_files[0]
             with open(page_file) as f:
                 pages = json.load(f)
 
@@ -135,6 +222,7 @@ def main():
 
         except Exception as e:
             print(f"[✗] Error downloading batch {batch_num}: {e}")
+            print(f"[!] Stopping at batch {batch_num}. Partial download may be available.")
             break
 
     print(f"\n{'='*80}")
@@ -153,8 +241,12 @@ def main():
         'estimated_positions': f'{start_pos} to {current_pos}'
     }
 
-    with open(output_base / 'download_info.json', 'w') as f:
-        json.dump(download_info, f, indent=2)
+    try:
+        with open(output_base / 'download_info.json', 'w') as f:
+            json.dump(download_info, f, indent=2)
+        print(f"[✓] Saved download metadata to {output_base / 'download_info.json'}")
+    except Exception as e:
+        print(f"[⚠] WARNING: Failed to save download metadata: {e}")
 
 if __name__ == '__main__':
     main()
diff --git a/downloader.py b/downloader.py
index 7bd3bd9..bc422b0 100644
--- a/downloader.py
+++ b/downloader.py
@@ -239,44 +239,86 @@ Examples:
     # Load credentials from headers.json
     headers_file = Path('headers.json')
     if not headers_file.exists():
-        print("[✗] headers.json not found!")
-        print("\nCreate headers.json with:")
+        print("[✗] ERROR: headers.json not found!")
+        print("\nCreate headers.json in the current directory with:")
         print('  {')
         print('    "headers": {"x-adp-session-token": "..."},')
         print('    "cookies": "session-id=...; ..."')
         print('  }')
         sys.exit(1)
 
-    with open(headers_file) as f:
-        headers_data = json.load(f)
+    try:
+        with open(headers_file) as f:
+            headers_data = json.load(f)
+    except json.JSONDecodeError as e:
+        print(f"[✗] ERROR: Invalid JSON in headers.json: {e}")
+        print("\nEnsure headers.json is valid JSON format")
+        sys.exit(1)
+    except Exception as e:
+        print(f"[✗] ERROR: Cannot read headers.json: {e}")
+        sys.exit(1)
+
+    # Validate headers structure
+    if not isinstance(headers_data, dict):
+        print("[✗] ERROR: headers.json must contain a JSON object")
+        sys.exit(1)
 
     cookies = headers_data.get('cookies', '')
     if not cookies:
-        print("[✗] No cookies found in headers.json!")
+        print("[✗] ERROR: No 'cookies' field found in headers.json!")
+        print("\nEnsure headers.json contains:")
+        print('  {')
+        print('    "cookies": "session-id=...; ..."')
+        print('  }')
+        sys.exit(1)
+
+    if not cookies.strip():
+        print("[✗] ERROR: 'cookies' field is empty in headers.json!")
         sys.exit(1)
 
     adp_token = None
     if 'headers' in headers_data:
-        adp_token = headers_data['headers'].get('x-adp-session-token')
+        if not isinstance(headers_data['headers'], dict):
+            print("[⚠] WARNING: 'headers' field is not a JSON object, ignoring")
+        else:
+            adp_token = headers_data['headers'].get('x-adp-session-token')
+            if not adp_token:
+                print("[⚠] WARNING: No 'x-adp-session-token' found in headers")
 
     # Download
     downloader = KindleDownloader(cookies, adp_token)
 
     # Override start position if specified
     if args.start_position is not None:
-        metadata = downloader.start_reading(args.asin)
-        revision = metadata.get('contentVersion', '')
+        try:
+            metadata = downloader.start_reading(args.asin)
+            revision = metadata.get('contentVersion', '')
 
-        # Download from custom position
-        tar_data = downloader.render_pages(args.asin, revision, start_position=args.start_position, num_pages=args.pages)
+            # Download from custom position
+            tar_data = downloader.render_pages(args.asin, revision, start_position=args.start_position, num_pages=args.pages)
 
-        # Extract
-        output_dir = args.output or f"downloads/{args.asin}"
-        print(f"[*] Extracting to {output_dir}/...")
-        extracted_files = downloader.extract_tar(tar_data, output_dir)
-        print(f"[✓] Extracted {len(extracted_files)} files")
+            # Extract
+            output_dir = args.output or f"downloads/{args.asin}"
+            print(f"[*] Extracting to {output_dir}/...")
+            # Ensure output directory exists
+            Path(output_dir).mkdir(parents=True, exist_ok=True)
+            extracted_files = downloader.extract_tar(tar_data, output_dir)
+            print(f"[✓] Extracted {len(extracted_files)} files")
+        except requests.exceptions.RequestException as e:
+            print(f"[✗] ERROR: Network request failed: {e}")
+            sys.exit(1)
+        except Exception as e:
+            print(f"[✗] ERROR: Download failed: {e}")
+            sys.exit(1)
     else:
-        downloader.download(args.asin, num_pages=args.pages, output_dir=args.output)
+        try:
+            downloader.download(args.asin, num_pages=args.pages, output_dir=args.output)
+        except requests.exceptions.RequestException as e:
+            print(f"[✗] ERROR: Network request failed: {e}")
+            sys.exit(1)
+        except Exception as e:
+            print(f"[✗] ERROR: Download failed: {e}")
+            sys.exit(1)
 
 if __name__ == '__main__':
     main()
diff --git a/headers.example.json b/headers.example.json
new file mode 100644
index 0000000..10dfddb
--- /dev/null
+++ b/headers.example.json
@@ -0,0 +1,6 @@
+{
+  "headers": {
+    
+},
+  "cookies": ""
+}