For some reason launching games from my USB HDD does not work. Nintendont recognizes the disk and finds the games, but after launching a game I just get a black screen. The games launch fine from the SD Card.
The Disk is a 500GB WD Blue which has a 250GB FAT32 Primary partition (the rest is unallocated). Here's the file system info for that partition:
"Sectors per Cluster: 64 (32768 bytes)
Number of Fats: 2
Reserved Sectors: 32
Sectors per FAT: 64225
Root 1st Cluster NO.: 2"
Nintendont version is V3.373 (Sep 29 2015 build).
The partition also has a folder for Wii WBFS files which load fine in USB loaders.
I'm using Wii U's vWii, but I tried it on a regular Wii and it's the same problem. SD works, USB HDD doesn't.
EDIT: Tried a 8GB USB Flash Drive. Worked flawlessly.
Tried to put a 500GB Seagate HDD in the USB adapter. Whole drive formatted as a FAT32, 32KB cluster, primary, etc. Same thing, Nintendont recognizes it and finds the games, but freezes to a black screen after loading a game.
Maybe it's a compatibility issue with the USB HDD enclosure/adapter. It's a CnMemory Airy.