Kat wrote:

In message , Paul Corfield
writes
My guess is that the gates at South Woodford didn't let you out because
there was no recorded entry point given that you had travelled beyond
your zonal availability. The system needs to know where you entered to
calculate any pre-pay deduction as you could have entered at Zone 6 at
Epping or equally Zone 5 in West London.

Even under those circumstances, the gate will show a 24 code but will
open and he wouldn't have been able to use the Oyster subsequently until
the unresolved journey or Pre Pay debit had been cleared.

....but there was no unresolved journey. It worked fine when I next used
it (the next day).

In a way, whether Paul is right or wrong, it seems to make more sense,
logically.

If Dave can remember the code which showed it might be possible to work
out what was going on. It's much more likely to have been a
communication error between the Oyster and the gate.

'Fraid I don't know - neither me nor the SAs looked (well, they might
have done, but they didn't comment). Possible, though it would have been
a bit of a coinkidink do have stumbled upon a dodgy gate as well as
everything else...

Ah well, we live and (don't) learn!