Make sure that you have the same level of folders above the library file that the default 2012 structure uses.
Welcome to the forum.
Another option would be to open the material file from 2012 into notepad and have your old one open at the same time and try cutting and pasting a portion at a time into the new one. See if this method excepts your existing materials.
I would also ensure that you have a solid backup of both files before doing this.
I ended up making a copy of the file and just throwing on my desktop to have an extra one and when I tried that through the tools-options-system options-file locations-material databases, everything worked fine. weird. thanks for all your help