I've just finished making a mine, interior cell and decided to connect it to the outside world, something I've done a 100 times and more. Setting up the teleport went fine and I went in game to test - all was good. Back to CK to add some final touches and navmesh. Clicked on the inside teleport marker and CK crashed. No problem seen many crashes in CK, restart. Try to load my cell - crash, again - crash. Go in game to test teleport, attempt to teleport into interior cell - game crashes, again and again. Restart PC - same thing. Start CK again, go to exterior teleport marker, remove teleport (hoping this was the reason as it was the last thing I'd done before crashes started), tried to load my cell - crash. I can load any other interior cell except this one. Have verified files for CK.

I have no idea why this is happening I hope you guys can give me options. Thanks.

Maybe start with the simple stuff - Have you got all the right Data Files loading?

This happened to me once when I'd accidentally deleted a 'cave shelf' piece that I'd used a lot of in the interior...

Never did fix it, had to start again.