How about trying the 01.02.15 firmware version?
** Here things are a little bit different. I still can’t see contents of card through the player when navigating through music->folder->external but I can’t see contents of the card when viewing through WMP or my computer either. There is just a “empty” folder called MSC , whereas on firwares 01.02.16 and 01.02.18 I was able to at leaset see the contents of the card when viewing through WMP or my computer.
This is a clue. How did you transfer the files to the card, in MTP or MSC mode? First off, re-applying, updating or back-dating the firmware will reset the USB mode to Auto Defect which defaults to MTP mode whenever possible. If your player is connected in this mode, you will see an MSC folder, but your computer will not be able to see or access any files within. Same is true the other way. The problem with the Auto setting is that you never know which mode it is connecting in if you don’t pay attention to the way it shows up in Windows Explorer. This can lead to some files being transferred in MTP and some in MSC, resulting in mass confusion and problems for you, the user.
Best to pick a mode depending on your usage patterns and manually set the player to that mode. There’s a good reason why the Auto Detect setting is referred to as Auto Defect. If you use protected or DRM-crippled files (like from Rhapsody, Audible or any subscription service) MTP is required to transfer over the ‘permission’ keys along with the file allowing it to play. If you don’t use a subscription service, it’s best to use MSC mode.
I’m guessing your files were transferred using MSC mode; now it’s connected in MTP so that is why you’re seeing the MSC folder with nothing in it. Try changing the USB mode to MSC (Settings > System Settings > USB Mode), re-connect and see if you can now see your files. You won’t see an MSC folder, but instead you’ll see the root directory with a Music folder. Your files should be safely tucked in here.
If you use the regular database (not Folders > External or MicroSD) does any of the files (songs) show up?
** Yes I can see files and though I’m not actively confirming each file, at a glance it looks like everything is there.
Good, so the files are there and are catalogued by the database. Changing the USB mode as suggested above shouldn’t necessarily affect the operation of the player when not connected to the computer, but it may. With the unit in MSC mode (and unplugged), try accessing the Folders option again and see if it shows your files on the card.