The file must be in /dev_hdd0/game/PKGI00000/USRDIR/ (for the installed PKGi). If you install PKGi to a different folder (like using a standalone version), the path changes. When in doubt, use the official release from aldostools.
The TXT file follows a pipe-separated format ( | ). pkgi for PS3 typically expects data separated by pipes. pkgi ps3 txt
: Tells the app which games, DLC, and updates are available. the path changes. When in doubt