The interesting thing is that with the edits the restored data structure store/retrieves just fine! Forgot to mention that. There must be an extra byte or two in the original that is triggering the behaviour but where....and what.....

Without a test case data structure it is like looking for a very small haystack in an enormous pile of needles! Did I mention I did not like the author's macro mania much yet ;-) As soon as you have a test case (and the croak will get you one provided you test and save it) it should be relatively easy to track down the issue(s)

Storable is a module I use all the time, as do many others. We can all do without it randomly crashing. Good luck.