Message #679

From: Roice Nelson <>
Subject: The School of Hard Knocks
Date: Tue, 23 Jun 2009 00:34:45 -0500

Dear All,

I got a stomach sinking email today from a member who accidentally overwrote
an almost completed solution in Magic120Cell. 17000 moves had been done.
MC5D and Magic120Cell do not make any automatic backups of log files
(something I now plan to change). When using MC4D, I’ve always made copies
of my log files at milestone points from paranoia, and I think this is a
good habit when investing so much effort in a solution.

As with many programs, be aware that using "Save" instead of "Save As…"
can be dangerous if you are not making log file backups yourself. What
happened in this case was that the puzzle type was switched to investigate
something (which reset the state in the older version of the program being
run), then "Save" was used. In the version that has been online since
September, you’d have to go more out of your way for an accidental overwrite
like this because changing the puzzle type no longer resets the state.
You’d have to manually reset the state from the options menu, then save.
That behavior is perhaps reasonable, but I will also make the program more
defensive by making "Save" do a "Save As…" if the puzzle has been reset.

Thoughts on other ways to improve the defensiveness are welcome, but I
wanted to send out this notice to help avoid this happening (I really hope
to avoid this kind of grief again). I also encourage people to make sure
they have the latest versions if they are actively working on solutions.

Take Care,