Uploaded files are not visible

I have uploaded numerous mp4 tutorial files I use on a regular basis, and they are not visible (I did not hide files).  They were not visible at all after their upload.  I initially thought there was an error were issue with the upload, but when I went to upload a single file once that is complete I was told in a dialog box is a duplicate file name.  The duplicate file is visible; however, the original upload file is not.

Thank you for your assistance.