iTunes shows my playlists on PC but won

I recently upgraded my PC, adding a brand new SSD as my C drive and reinstalled Windows 10 (64-bit). My old C drive is now the D drive, so now my iTunes Media Library is on my D drive.

I uninstalled the version of iTunes that was on the (now) D drive, and performed a fresh install of iTunes (ver. 12.10) onto the C drive. The path shown in the Advanced Preferences iTunes Media Folder Location directed to a Media folder in C drive - which didn't actually exist.

I changed the path to direct it to the original iTunes Media folder in my D drive, but all I'm seeing are my playlists on the left side of the screen, however, when I click on any of the playlists, no content is shown.

I copied the entire iTunes Media folder from the D drive to the C drive and changed the path accordingly, but I still have the same result.

When I click on 'Songs' (or any other sub-heading) under 'Library' near the top left corner of the iTunes window, all my files are shown on the right. I'm really hoping I don't have to manually drag them into the playlists now.

I've tried restarting the PC after installations, making changes, etc., and have authorised the computer again successfully too. No change.

I've also tried the following importing options from the original Media folder location in D drive...

...which resulted with...

This also happened when trying to import the same file type from the C drive.

I then tried importing...

...which resulted with...

When I tried importing this file type from the C drive...

...the playlists on the left side of the screen showed three more of each playlist, so I now have four of each playlist, all still with no content.

[NOTE: This duplication issue may be unrelated to my media files not being found. I've previously had troubles with playlists being duplicated in my iTunes and on my devices when syncing, most likely a fault of my own. Assistance avoiding this in future would be also be greatly appreciated].

If anyone can offer any suggestions or solutions to why my media files aren't appearing in my playlists, I'd REALLY appreciate it, since I haven't been able to find answers anywhere online.

Thanks in advance, guys!

Cheers.