Can't assign a seat

Hi
The seatmap for my flight VS085 in March has just become available. I'm trying to assign seats. There are plenty of available seats however when I try to assign seats I get a message saying 'We're sorry, the seat(s) you have chosen are not available. You are still shown in your original seat(s).'
I am definitely selecting red A (available) seats. I've tried selecting a number of different available seats however get the same message. The problem is that I have no original seat, according to the seat map I'm not sitting anywhere at the moment.
Any advice? I notice someone else on the board was having difficulty changing seats however their map at least shows they have a seat somewhere on the plane.
Is this a website glitch?
I'm booked through VH if that make a difference?
The seatmap for my flight VS085 in March has just become available. I'm trying to assign seats. There are plenty of available seats however when I try to assign seats I get a message saying 'We're sorry, the seat(s) you have chosen are not available. You are still shown in your original seat(s).'
I am definitely selecting red A (available) seats. I've tried selecting a number of different available seats however get the same message. The problem is that I have no original seat, according to the seat map I'm not sitting anywhere at the moment.
Any advice? I notice someone else on the board was having difficulty changing seats however their map at least shows they have a seat somewhere on the plane.
Is this a website glitch?
I'm booked through VH if that make a difference?