LR only reads image files. Please give more details on what you are doing, what you are seeing.
Not enough information. Are you talking about files that have been imported? Or, are you talking about all the files on the EHD? What operating system? Is this a problem that just started? The more details you can provide, the better will be the assistance you receive.
I use Adobe Photoshop Lightroom 5 for Windows.
This problem started about 2 weeks ago, but I can't get support to help me.
I am talking about files that are on my EHD. When I open LR and open the external drive folder, some of my files are not showing.
Lightroom is not a file browser, it will not show all the files in a particular folder unless those files have been previously imported into Lightroom. So are you talking about photos that have been previously imported into Lightroom?
Can you give us an example of this problem, preferably with a screen captures so we can see what Lightroom is showing and what your operating system says?