It appears that today the diversions mean that "the headcode is not recognised by the computer system so no reservations are possible", we've just been told.
It's unclear if that is just the train I am on, or all trains.
There is also very unclear information about the status of reservations; previously LNER simply used to say they apologise for the lack of reservations and stated that if your reserved seat was already occupied, to find an alternative seat.
However on my train today they are making all sorts of muddled and confused statements such as "we apologise if someone inadvertently sat in your seat" which is open to interpretation. The TM even had the cheek to say that only tickets for this train are valid! Well, they have to accept my ticket, whether they like it or not, and I have the relevant page on the LNER website open for inspection if they try to have an argument!
LNER do seem to be able to make a non-ideal situation even worse at times; while there are many good people in the company, some of them really aren't passenger focussed enough.