Thanks, Mohit, but I've read through all of that. I'm not sure what you thought I should glean from it. I'm not referring to customized or newly created profiles, but the profiles I have been using since I first purchased Lightroom.
Take, for instance, the Voigtlander 15mm for Leica M. Even though it is still currently located in Library>Application Support>Adobe>CameraRaw>LensProfiles>1.0>Voigtlander AND Applications>Lightroom>Contents>Resources>LensProfiles>1.0>Voigtlander
it no longer shows up in the menu I posted the screenshot of in my first post.
Before 5.7.(1) it did.
Are you working on a RAW file or a JPG file? The lens corrections are mostly for RAW files.
Yes, RAW dng from my Sony r7 (I stated that I have been using the lens correction profiles for years. How could I have done that with JPG files?)
Also, I just purchased the Lightroom 6 upgrade, and the problem persists.
Could this have something to do with Camera RAW? There was an update in Dec I believe, and there's a chance I hadn't noticed between then and now.