Rock Band DLC needs the decrypted songs folder in addition to sce_sys to work.
I have no idea how to decrypt it without having a properly activated PSN account, but you can build custom DLC using LibForge
Do this:
Get an external HDD and format a partition on it (FAT32)
Download 'FSTOOLBOX' app for HBC and do a NAND Dump.
Move all the contents from folder SD:/FSTOOLBOX to USB:/nand
NOW you can run your GH5 with uLoader's DLC Hack (It will download the DLC to your HDD instead of your NAND)
If...
I use uLoader 5.1D (Latest).
You can grab your cIOS222 for GH/RB games from cIOS 222 Installer V4
In the menu just select install IOS222, then choose Use IOS 38 merged with 37
Also you can use the DLC hack on uloader (Loading DLC from HDD)
I had the same error.
Just Run the game with uLoader & IOS222 rev 4 (37+38) and you'll can download again.
Then you can play with the DLC in any other loader (Or with DarkCORP/cIOSCORP)
Ill have to format mi HDD then.
Is there any problem having 3 partitions in the disc? RawkSD 3 will recognise the FAT partition?
(P1 = NTFS (4GB+ files), P2 = FAT, P3 = WBFS)