The "media offline" message happens when VV3 can't find specific files. Have you moved the files? Renamed them? I have over 500GB storage on a variety of devices including removable drives and virtual drives which need to be mounted and since I move them around and/or don't always mount them all always, I sometimes forgot where I put such and such file.

Do you see the message where VV3 asks to help you locate the offline files? It can search all your drives or you can tell it where to look.