You have not shared info about the SAS variable MAIN and its content. Also, it is unclear exactly what SAS variables contain in your DATA step.
Suggest you consider re-posting another REPLY and add this SAS code to your DATA step (using COPY/PASTE to share your exact SAS log, not just partial code info):
PUTLOG _ALL_;
STOP;
Also, consider (from SAS Language DOC) that CATX function can have multiple parameters -- it may be suitable to add L1_0 as then third positional parameter argument to the function call.
Scott Barry
SBBWorks, Inc.