server/AyaNova/biz/TagUtil.cs

@@ -27,6 +27,7 @@ namespace AyaNova.Biz
 
         public static string NormalizeTag(string inObj)
         {
+            if(string.IsNullOrWhiteSpace(inObj)) return null;
             //Must be lowercase per rules 
             //This may be naive when we get international cust omers but for now supporting utf-8 and it appears it's safe to do this with unicode
             inObj = inObj.ToLowerInvariant();