Hi wivsteve
I'm not with Laminar Research, just a fellow simmer in the UK, but a couple of questions:-
1. The above message refers to navdata files made for X-Plane 10, are such files on your PC?
2. Is the C:\X-Plane 11\Resources\default data\CIFP in place (X-Plane 11 default navdata) and is the format of the files contain in it made up of 3 or 4 alpha numeric characters (alpha being in upper case, as per the message above) i.e. EGLL.dat or 1R8.dat?
3. Do you have any navdata in your C:\X-Plane 11\Custom Data\CIFP folder, with a similar format to that above? This data would have come from Navigraph or similar
4. Could you upload your X-Plane 11 Log.txt file to this post, so that I and others with a broader knowledge base than myself, can review the whole file?
If you're not sure how to upload the Log.txt file, please click on the following link to see some instructional PowerPoint slides that I have prepared :-
http://questions.x-plane.com/?qa=blob&qa_blobid=3269663564594867247
Regards