It's virtually empty, so how could all the seats be reserved to cause the error on the ticket machine?

Approach train with a few minutes to go. Police and security staff are escorting some people off. Words being had but doesn't seem too heated. Is this the right train? No indication. I ask someone, it is the right one.

Try to log in to Trainline on my phone. Can't get the password right. Could reset but bit of a drag on my phone. Text my wife, she buys me a ticket and sends it to me.