Hey all,
So I encountered this issue too on P3Dv4.5, and after reading through this thread I admit I figured I'd have a better chance fixing it myself with a bit of tinkering.
I was able to resolve this by disabling the file "ENCN_terrain.bgl" located in the airport scenery folder (/adding ".off" at end of filetype). Quite a large file...566mb for me. Looks like Gaya has tried to include some of the rolling hills terrain around the airport, and I suspect some of that data may not play well with other third party addons (Norway Airports, FS Global).
Full disclosure, I use both Norway Airports freeware & the FSGlobal payware mesh, so any terrain data that I may have 'lost' by disabling "ENCN_terrain.bgl" is likely covered by my own use of FSGlobal, so I am unsure if this trick will work for everyone.
Image link of the file organization; this forum's upload system timed-out when attempting to upload directly to this post.
https://i.ibb.co/XWh8MFC/ENCN-Terrain.png
EDIT / FOLLOW-UP:
In further testing, this workaround causes a small terrain anomaly around the RWY22 end of the runway. I've created a small additional CVX file that can be placed in your airport scenery folder, see attached.
Ultimately, these 2 steps fixed the issue for me; but given I am on P3Dv4.5, am uncertain how this will work in v5.
1. Disable ENCN_terrain.bgl in airport scenery
2. Place the attached CVX file to airport scenery (should not need to overwrite anything).
Please note: This CVX file was named intentionally in order to sit directly between the ADE file and original CVX provided by Gaya. I cannot stress enough - do not delete the original "ENCN_AIP_CVX.bgl" ! This is how my folder looks.
This is how ENCN now appears for me:
Of course, this should be considered strictly as a band-aid / duct-tape / interim solution until Gaya can provide an alternative terrain file.
Hope this helps!
ENCN_AIP__CVX.bgl