put multiple updates of datastores in a try catch, if update fails in one or many uf the datastores no exception is fired, but if checked the update 
ifsreturning -1 but no option to get the update error :
try{
lds1.update(true,PbResultStyle.Flags);
lds2.update(true,PbResultStyle.Flags);
}
catch (Exception e)
            {
                as_err = "ERROR: " + e.ToString();
                return -1;
            }