Thanks Tom. This helped me spot where my issue lied. Due to not all files having relavant tab names and those with tab_names often having zero obs was seeing unsynchronised file names based on load iteration. File name associated with table and that associated with contents weren't matching when the file didnt have the proper tab so it would break with "data doesn't exist" error. My Solution was to do nested due loops within a macro theat calls the Tab name : %macro alias(PROCESSED) and added this code based on obs count: /*Get the member names in the library */ proc contents data=indata._all_ out=work.contents noprint;run; /*accounts for tab iterations with null observations*/ data _null_; call symput('obscnt',0); set work.contents; where memname in ("&tab_name"); call symput('obscnt',_n_); stop; run; %If &obscnt=0 %then %do; %put 'There are no records in a dataset.'; %end; %else %do; proc sql noprint; create table work.contents_with_file_name as select distinct memname, "&file_name" LENGTH=200 as file_name_contents from work.contents where memname in ("&tab_name"); ;quit; %if &i = 1 %then %do; data append_contents; set contents_with_file_name; run; %end; %else %do; data append_contents; set append_contents contents_with_file_name; run; %end; THis got me to where I was able to compile datasets without null values into the final output for that single tab name. I followed by calling the macro separate times based on the subsequent tab names. Thanks so much for your help as it pointed me in the right direction. ... View more