File Manager

I am trying to add a build to my kodi on my android tv box. I went to file manager and added the URL and went back to Systems selected addons then install from zip file. Now when I selected the source that I added all the I get in the next window are just two dots. No files in the zip folder. I tried with another file, same thing. Can anyone tell me why this is happening. I checked and rechecked and the URL is spelled correctly. I have restarted Kodi. Any suggestions?