When TRACE LP is ON, A-Shell displays the printing process is some detail, and includes something like:
Trace: Prefix: sys:mdunes.pfx, Suffix:
Trace: concatenating.
Trace: .../mdunes.pfx to .../tskaaa.003
Trace: .../srvdsp.lst to .../tskaaa.003
Send .../tskaaa.003 to aux/local ptr

The problem is, if because of a permissions violation A-Shell can't actually read the pfx file, there is no trace error message indicating this problem. It would be nice if trace could include an error message when it couldn't read the pfx file. It might even be worth an error message when TRACE LP is OFF.

I'm not sure how to justify this, but for some reason it is logging those errors to the syslog() facility rather than the normal ashlog.log. Obviously not very useful unless you knew to look there, and even then it makes little sense. It's on the list to fix...