Which camera are you using?
Have you updated to the latest Lightroom version of Lightroom 6.6.1
Also what is the exact error message? Post a screenshot if possible.
Did your camera shoot RAW+JPG? If so, there is an option in LR that you can turn on or off that prevents Lightroom from seeing the JPG. Go to Edit>Preferences, turn on the option "Treat JPEG files next to raw files as separate photos"
No. I just have a JPEG that I want to alter in Lightroom and it won't recognize it to import it.
So please explain in lots of detail what you mean by
Lightroom does not "see" any JPEG file
Also, please show us a screen capture.
Please state your exact version NUMBER of Lightroom. Do not state that it is "up to date" or "most recent".
There must be something else happening. Lightroom should import JPEG's from any camera. There isn't any special support needed for any camera as far as JPEG images is concerned.
On the import page I go to the folder where the picture is and it is not "visible" (not there for me to choose), to import it. If I right click on the file name, it does not list Lightroom as a program that will open it.
Can you show us a screen capture?