Could you please elaborate the exact issue?
Which lens profiles are you talking about? Did you create some custom profiles or the default ones are missing?
Which version of Lightroom do you have?
I speak of the "lens profiles" directory contained in the Lightroom/resouces/lensprofiles with .lcp extension for correcting the optical defaults.
these are the profiles included with Lightroom 6.4
Those profiles should automatically reload on installation of Lightroom.
If they are missing, you might want to reinstall the program.
That's what I did but it lacks all the files that were loaded with previous versions, I have only the files of the update from 6.1 to 6.4
Thanks a lot
After yours advices every things is OK