Go to Channels, then press "start" and click on "copy sysconf from real nand", that helped me.
Or buy the Samsung FIT Flash Drive, because it is the official supported Drive for PortablizeMII.
@CivilKink This was an old thread, last replied to 2 years ago. Try to avoid bumping old dead threads.
Anyways, PortabilizeMii has essentially been deprecated by BBLoader written by Aurelio. BBLoader also has better USB support compared to PM. If games show up but don't boot it's probably that your USB drive isn't compatible with PM/BB.
If you're ok with waiting for things like virtual console and the other features that are being worked on you should try using BBLoader. The thread about it is here: https://bitbuilt.net/forums/index.php?threads/bbloader-v1-0-beta.3564/
If you're hellbent on using PM still you should ensure that you're using one of the recommended drives, which now basically means a Kingston G2 USB to microSD adapter (link). The issue of GC Games working but Wii games not usually indicates a drive compatibility issue.