MD> Can I just zip the entire mystic directory into 1 file as a backup
 MD> mystic.zip?  My hope is that 
 MD> if I do that, I will have something to fall back on.

Yes that would be maybe even overkill but a good idea to do that if you can.

 MD> I assume I would then download the latest .zip update file, unzip it
 MD> into it's own directory 
 MD> and do the upgrade from there, following the instructions of course.

I don't know which version you are upgrading to but yes you would unzip the new one in a temp directory and there should be an upgrade.txt to follow.

The upgrade between A46 and A47 is one of the more painful ones unfortunately.  I waited too long in between releases on this one.

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--- Mystic BBS v1.12 A48 2022/03/26 (Windows/64)