Thank you again.
As I had downloaded the the files this week, I followed your advice you gave for a similar problem to LoïcAF in the following thread
http://www.fsdreamteam.com/forum/index.php/topic,12836.0.html as I had also made a customised livery for this airport.
By removing the paintkit and the _USER folders left, this resolved my problem. I had not realised that removal of the paintkit was necessary.
Now I will need to make the livery changes again.
Regards.