Aircraft not defined

During flights on fsx I continue to get a message, "aircraft model not defined". What does this mean and how can I fix it?

Welcome to the forums
This is quite interesting,I have actually never heard of this,I'm sure someone here will be able to help.
Does this happen before or after loading your flight?

Yes, welcome too peteacher!

Now, are you telling us the whole story or are you involved in some clandestine operations here...

Just in case you've experimented with 3WIREX, have a look at this:

http://www.3wirex.com/aircraft/

That's all I've been able to find so far, let us know if it's relevant to your problem.

I too have had this error. Its only with the Abacus FD5 right? I don't know what it means but I get it when in the hornet (not the superhornet I believe) when I to put the tailhook down.

Thanks. Uninstalled FD5 and no more problems.