Update utils.py

utils.py

@@ -158,6 +158,11 @@ def formatera_historik_html(historik: list) -> str:
 
 def spara_nedladdning(innehall: str) -> Optional[str]:
     """Save text file for download"""
+    # Check if input is valid
+    if not innehall or not isinstance(innehall, str):
+        logger.warning("Invalid input for file download")
+        return None
+        
     try:
         timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
         path = os.path.join(Config.TEMP_DIR, f"vips_anteckning_{timestamp}.txt")
@@ -169,7 +174,6 @@ def spara_nedladdning(innehall: str) -> Optional[str]:
         logger.error(f"Error saving text file: {e}")
         return None
 
-
 def exportera_csv(alla_resultat: list) -> Optional[str]:
     """Export all results as CSV"""
     if not alla_resultat: