My 'working' drive is B:, it doesn't show up on import nor the destination list, even though I can open a catalog off of it. It's 2017, why isn't this fixed yet?
Agreed. This has been discussed for several years. No fix yet.
Feel free to add your vote there.
For the moment I have to go into Computer Management -> Disk Management, and instead of changing the drive letter I add a mount as an empty NTFS folder on another drive that is visible. (As a result I have to import/destination in LightRoom as E:\BDrive\Catalog instead of just B:\Catalog).
But it's really stupid, because I also use A: as my SD card reader (though I'm normally copying my whole SD content to my 'dump' folder... which happens to be on B:...)
PS: Added a vote.