Empty Folder Is Not Empty

I have a folder on an external drive which Explorer shows as empty. However if I copy that folder to another drive there are over 5,000 files in the copy. Also the new folder still shows as empty. What should I do?
Thank you so much
Michael Dietz

 

Not much to go on but open a command prompt and try this -

attrib -h <folder path>\*.*

 

Thank you Earthling. I tried your suggestion and it said the folder/file wis not found. So I tried a CMD of dir L: and the folder was not listed. I think that I had deleted the files in the folder but Explorer did not erase the folder name. Problem solved by my deleting the folder again which occurred.