It's possible that some of the water resistant coating has gotten into the socket for µSD card socket and is causing issues. The only time I played with this, I ended up using a wood toothpick and a lint free cleaning cloth to clean the socket.
Unless you formatted the µSD card while it was in your PC, it should not have had any effect when you replaced it in your Libra 2.
You can request a replacement image for the Libra 2 in the
Kobo µSD Card Image Requests thread.
However you will need to have Private Messages enabled before you can be sent the link. If you don't see that option in the "Edit Options" of the User control panel, you should post in the
Requests to enable Private Messages thread to ask for PMs to be enabled.
Once PMs are enabled, please post your request in the
Kobo µSD Card Image Requests.