Ok, I apparently managed to recover my wallet by importing the seed into Electrum with the BIP39 box, and the balance is 0 Btc.
However, if I create a "watch only" wallet and add my old address, I see the balance is 5mBtc.
This means you didn't recover the wallet into Electrum. However, this does imply that the seed words were accepted, i.e. they are valid BIP39 words and they pass the checksum test.
I suspect that the "derivation path" is incorrect. Electrum should have used a path of
m / 44' / 0' / 0' . (The apostrophes are important.) Try paths of
m / 44' / 0' and
m / 0' , and maybe even
m .
FYI, in the default derivation, the m means master seed, the 44 means BIP44 standard, the first zero means Bitcoin (vs. altcoins), and the last zero means the first account from this seed. The apostrophes select a specific algorithm for this stage of the path. In use, Electrum will append
/ 0 / 0 and
/ 1 / 0 to the path. The first digit selects receive addresses (0) or change addresses (1). The last digit selects which address in the sequence. For example, the path of
m / 44' / 0' / 1' / 1 / 6 gives the 7th change address of an alternate Bitcoin account.
