njok,
I've downgraded my Story to 1.61, and then back to 1.71, with no ill effects. (I did it because someone suggested some of the Story's limitations with certain document formats had been introduced in 1.71, and weren't there before, but it didn't seem to be so.)
Have you tried copying the version 1.71 hex file onto your story and letting it "update" - even if it is to the same level - to see if that solves your freezing issue?
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