server/AyaNova/biz/ContractBiz.cs

@@ -146,6 +146,10 @@ namespace AyaNova.Biz
                 try
                 {
                     Contract dbObject = await ct.Contract.SingleOrDefaultAsync(m => m.Id == id);
+                     if (dbObject == null){
+                        AddError(ApiErrorCode.NOT_FOUND);
+                        return false;
+                    }
                     ValidateCanDelete(dbObject);
                     if (HasErrors)
                         return false;