Error Trap display intermittent problems

I have found that when I kill all my variables then I can view the error trap. It's only when they are set that I cannot see it.

This is a generic error trapping comment and may or may not be helpful, but a common bug in error handling has to do with the use of both $ZTRAP and $ETRAP. VistA is supposed to use $ETRAP exclusively with GT.M, but it is possible that there is some use of $ZTRAP for another MUMPS implementation that is not adequately protected and which is getting set.

Joel has already done some work on this; my understanding is that he's identified and fixed the issue that caused the error trap to fail when variables are set. Joel - feel free to comment more on this.

That said, there are at least two errors with the error trap that I am aware of. One is consistent and seems to be the one Robert is describing - if you have no variables set, this does not appear:

          $STACK=8 $ECODE=,M26,Z150374122,
          $ZSTATUS=150374122,IHSXQY0+5^XTER1A,%GTM-E-ZGBLDIRACC, Cannot access g
lobal directory /home/demo/DEMO,DEMO.gld. Retaining /opt/openvista/demo/globals
/mumps.gld.,%SYSTEM-E-ENO2, No such file or directory

The other is not always reproducible:

%GTM-E-IONOTOPEN, Attempt to USE an I/O device which has not been opened
                At M source location %XTZDAT^XTER