Hi John,
have you tried to re-create your content-file? This file is very important for the sim. When it´s a mess or when it´s corrupt, you see exactly such issues … therefore this file shouldn´t be changed manually without knowing what you do 
Worth to try?
- close the sim
- delete your
content.xmlfile (you find the correct location here) - start the sim again and wait till he is up and running
- close the sim now
- open the Navigraph Navdata Center and install the AIRAC cycle again
- start the sim and look if it´s solved
It´s really worth to try these steps …
Hope that fix your issue - crossing fingers,
Richard