I have Yubikey with the firmware version 1.0.8.
Its ATR announces "unknown" for support of TERMINATE_DF/ACTIVATE, so, "factory-reset" command of gpg frontend doesn't work.
And for newer version (4.2.7, which I don't have) it seems that it is supported, but it goes into terminated state (and not activated).
Both cases, the method in the page at Yubico works:
https://developers.yubico.com/ykneo-openpgp/ResetApplet.html
| rG GnuPG | |||
| rGf183b9768b42 g10: Simplify "factory-reset" procedure. | |||
| rGd63b7966cdd7 g10: Simplify "factory-reset" procedure. | |||
This may fix the problem for new version 4.2.7:
According to Achim, the specification doesn't require RESET and SELECT_FILE between TERMINATE_DF and ACTIVATE_FILE.
Even the test version of V3.3 card failed with GnuPG 2.1.22.
This fix won't work with older Gnuk, which expect SELECT_FILE between TERMINATE_DF and ACTIVATE_FILE, but its effect is just an error for ACTIVATE_FILE and factory-reset works well.
I am pretty sure that older cards required this behaviour. It might have been a workaround for a bug in scdaemon, though - I am not sure. So we should test this with all available card versions.