Recover Electron wallet with bad seed phrase I once created a bitcoin wallet with Electron using a hand crafted seed phrase (using the words of the valid word list that time). 

I now figured it was a bad idea, while it is possible to create wallets for abitrary seeds, a version number is encoded inside the seed, and thus it has some kind of format.

Now I just recovered the wallet from my seed phrase just to found it empty, no transactions inside.

I guess changes to the Electron code base broke the decoding of this hand crafted invalid seed so it now points to some other private key not matching my old wallet.

Is there any condensed documentation, how the usage of the seed phrase changed over time? How can I convert the old seed phrase to a working wallet?
Electrum used BIP 39 seeds for some time. So your seed may be a BIP 39 seed, in which case you will need to tell Electrum that you are importing a BIP 39 seed. When you are importing the seed, click the Options button and then check the checkbox for BIP 39 seed.