Use of GN/TL Key card at Intermediate Stations - code 57

[jimney]

I hold a season ticket between Brookmans Park and Elephant and Castle on a Key card.

For the last week when I have tried to exit at Potters Bar Station and break my journey (quite without the rules), the barriers have not let me through. Code given is 57 which the gateline staff inform me means the ticket is not valid.
Except of course, it is.

I have used my key card several times to exit at this station over the last few years. It still works fine at other intermediate stations - I entered and existed at both Finsbury Park and London Blackfriars within the last week. The ticket office in Potters Bar have checked my card and can see no issues.

The gateline staff assure me that I am mistaken, I have never been able to exit at Potters Bar using it (they informed me today that 'the gate must have been open'. I know I'm not going mad and have done so many times.

Does anyone know if there has been any software or policy changes recently that would cause this or has any other explanation? This is something I do regularly and it is going to be an absolute pain having to explain to the gateline staff every time what the issue is.

Thanks for any advice

 

[Watershed]

Code 57 means:

PPT INVLD: Location not covered by PPT (pre-paid ticket), barcode: NLC not valid

Its possible the barrier software has been changed since you last broke your journey there. Each station's barriers have to be manually configured to accept tickets issued to/from other stations, and AIUI there is quite a low limit on the number of such entries in the gateline's database.

I would contact GTR to complain. As a bare minimum, their gateline staff should manually read your smartcard and accept it that way. But really they ought to be fixing this.

Personally speaking, problems like this are why I am reluctant to get tickets loaded to a smartcard.