Go to the "Files" tab and click "Add" to select your Super Smash Bros. Brawl ISO. Plug in your FAT32-formatted USB drive.
The solution is splitting the file into WBFS segments. Here is everything you need to know about managing Super Smash Bros. Brawl in WBFS format. The 4 GB Limit Explained super smash bros brawl wbfs split
Go back to the "Files" tab, check the box next to Brawl, and select "Transfer" -> "Drive 1." Go to the "Files" tab and click "Add"
WBFS ManagerAn older tool that is less flexible than Wii Backup Manager but still functional if you are working with older WBFS-formatted drives. check the box next to Brawl
The software will automatically split the game into .wbfs and .w1f files in a folder named "Super Smash Bros. Brawl [RSBE01]." Troubleshooting Common Issues