sell plane fails "no plane selected"

I think the plane database is corrupted someplace. I bought 747F 25113 in MT 1FoxDeux on the UM cheap, so I could relist it so an AI broker would buy it and make me a profit. I bought 4 planes to do this, 3 I can list,

When I list 25113, at 210MIll, I get the error

"Error: No aircraft selected. Please try again.". I went to aircraft summary, saw the plane top left "planes with no routes", selected it, changed the price and voila! Worked for the other 3, fails for this one.

In addition 757PF 25933 has twice now lost all the slots on the routes allocated to it, and I've had to rebuy the slots. It's as if the plane is not flying, but it has been flying like this for the last 6 months without my changing anything. I think again db corruption someplace. I realise it has lost slots as I look at routes, then route overview then "routes not being flown" and the routes on this plane pop up again as having no slots!