Hi all, I've been getting the following error :" ERROR: The following columns were not found in the contributing tables: ..." when I run a query to create a table of dupicated ids.   The thing is I haven't changed the code, and it worked before so I don't understand why I'm getting this error message and am at a lost at how to resolve it.  If anyone can help that would be appreciated. Thanks. Below is my code: %let main= my dataset; %let id= my id; %let step= my step; %macro dups_table (dsin=&main); proc sql;     create table dups_&&step as     select *, count(*) as count     from &dsin      where &id ne 0 group by &step     having count(*) > 1  ; quit; proc print data=dups_&&step; title "Matched by &step."; run; %mend dups_table; %dups_table; ... View more