I, too, have long been vexed by the mysterious key derivation bug from the older (pre-0.39) versions of Electrum. Documentation on this bug seems non-existent.
-snip-
That is because the affected versions (
pre v0.34) existed before the official release of Electrum.
Only those users who are following its development and used the source code to run Electrum have experienced the bug.
So it's only normal that you cant find any documentation about the issue aside from the old release notes since it's not yet officially released at that time.
I have also been unable to find any documentation that explains how the master keys were derived from "old" seed version (non-bip39 wordlist). There doesn't appear to be a way to export a master private key from those types of wallet. Is that not possible? Does anyone know? Sorry, not trying to hijack your thread. I hope you have had better luck than I.
If it's just old seed (
pre v2.0, post v0.34), then you can simply restore it to the latest versions, it will be accepted as "
old seed" and it will restore the same wallet.
If it's for versions before v0.34, you may get better response by asking the core developers about how to reproduce the bug.
You can post it as an issue in Electrum's repo:
https://github.com/spesmilo/electrum/issues (
be accurate with the title)