Hello,
Thanks for the tip.
Yes, the script was running in the system context as is often the case with SCCM 2012.
Here's the change that I made.
For my program properties, under environment, I have changed the ' run mode ' to ' run with user's rights '
Looking at EXECMGR log, I see the program is executed in the user context.
I also see the program runs and succeeds, with exit code 0
That said, the Reading List tile is no longer on the start screen, but the Reading List app still appears in the Apps by name alphabetical list and can be executed.
Who would have thought this is such a rigmarole ?