So, it looks like there is sometimes a problem with the shadow table and sometimes not but whatever the problem, Allen's code recognizes it as an error and displays a message. I don't know that I have the time or the will to debug this problem for MS for free because they won't fix it anyway Maybe you can forward the issue and if they care, they can look at it.
Only way I can think of preventing users from directly accessing the table is to uninstall the full version app and only install the runtime version (that will eliminate the "left pane" from the equation).
AFAIK, not possible with A365.
You could delete the MSACCESS.EXE file but that might leave issues with registry entries. In any case, an Office repair would restore it