I recently updated to the new version, as well as cIOS r21dx2 base 56 in slot 249. Things seemed to be working fine, then as I was setting up some alt dol games, suddenly all games stopped loading. This is the black screen on load that sounds exactly like this thread:
http://gbatemp.net/t276152-so-i-upgraded-u...et-black-screen
So I wiped all USB Loader files off the SD, and did a fresh install. Nothing. I tried it out in CFG Loader… every game works fine. I have another Wii that I'm updating as well (same cIOS, same version of USB Loader GX) so I plug my harddrive and SD card in, and that Wii loads all games fine, even the alt dols. Plug the same back into my Wii, and nothing. Then I try the other Wii's harddrive in mine, and it starts working. Plug my drive back in… and that's working again now too.
I go through my list of 75 games testing each one. About half way through the problem comes up again, randomly. Now the other Wii's harddrive will not work, neither will the SD. After hours of frustration, the problem seemingly randomly goes away again. I get through some more games and then it comes back again, near the end of the list.
I narrowed down that it couldn't be a corrupted cIOS, as CFG Loader works flawlessly. It couldn't be the SD card, because the other Wii loads fine with the same card, and it can't be the harddrive for the same reason. So USB Loader GX must be writing something to NAND when it loads (certain?) games, and this somehow is messing something up.
I reasoned that the only thing that should change in NAND from a game loading is the game save file… so on a whim I went and deleted a random unused game save file. After that… everything started working again. After about another 30 game loads it stopped again. So I found another random game save and deleted it. Everything started working again. So with two tries now, this is starting to seem like a consistent work-around.
The only other thing I noticed…which may or may not be relevant… when I thought it might have something to do with a corrupt config file. Every time I would set an alt dol, Ocrina would automatically switch to on for that game.
Unfortunately I don't know the steps to reproduce this black screen (which sometimes, but not usually, loads to HBC), as it seemingly happens randomly, and is not cIOS or setting dependent… as I tried every conceivable cIOS (222v5b37, 223v5b38, 224v5b57, 249r21dx2b56, 250r21dx2b57) and settings combo to no avail. One game will load… then none will, with no tinkering in between. It could be that the game I load just before it stops working is trying to write a new game save file, because one isn't already present on the system… and maybe the loader isn't handling that correctly and causing a crash… but why would that effect every game, and why does it start working again randomly? And why does deleting a random game save file fix it? Here's hoping the problem can be narrowed down and fixed. I really like this loader, I've designed themes for it, I hope to be able to continue using it in the future.