When running SAS Stored Process code in batch, your job may fail due to a missing, or incorrectly configured _webout fileref. In StoredProcess mode, this fileref is used to stream all kinds of output, both text (html, xml, json) and binary (zip, some types of excel).

A reliable way to configure the _webout fileref in this instance (eg so a pdf can be written in chunks) is as follows:

filename _webout cache; 

Note - this feature appears to be undocumented.