What does your hard drive currently have on it in your FAT console? No usb over 4gb will usually work through the usb unless its Powered hard drive and formatted to Fat32.
Problem here is UsbloaderGX im pretty sure it uses 249 base 56 as a default for all games but you have base 57
And running v10beta can also run into problems well it use to anyway.
I personally use d2x-v8final 249/56 250/57 251/58.
And delete GXGlobal.cfg in Usbloadergx foler in apps it...
If your still having issues with black screens try deleting the CFG file in apps/Usbloadergx folder it will generate a new one when you strat it up again.
I have a gen 3 wiimotionplus controller with red sync button on battery cover it wont sync with wii classic pro controller plugged in or nunchuck and becomes non responsive when used with Nintendont.
I put the folder in wiiu/apps/WUPDownloader/ WUPDownloader.rpx meta.xml icon.png. And nothing it wont show up. Renamed rpx to elf and it showed the folder in hombrew channel. So why wont rpx launch for me or even show on my wiiu?
Do you know anyone near you that has a chipped or TSOP modded xbox you can borrow to get the eeprom? Only other way is to use Ponyprog and make an eeprom reader yourself.
If this was soft modded and if they used mech assault or splinter cell you should still have the save game on there as a back door to launch the exploit.