The mass: directory appearing empty in uLaunchELF (uLE) usually occurs because the USB drive is not using the specific file system and partition scheme required by the PlayStation 2.
: uLaunchELF and the PS2 generally only support the FAT32 file system. Drives formatted as NTFS or exFAT will not be recognized. ulaunchelf mass empty
It is critical to understand that "Mass Empty" is the same as "Mass Not Found." If uLaunchELF says "Mass Not Found," it means the USB device isn’t being detected at all (usually a power or hardware issue). "Mass Empty" means the PS2 sees your drive, but cannot read the file allocation table or partition structure correctly. The mass: directory appearing empty in uLaunchELF (uLE)