Lineage 2 High Elves: this package has an unknown signature

[Denza755]

Hello.
Can u help me please !!!
I develop a custom content for Lineage 2 java server High Elves and i need to work with client *.u files
U program can open High Five client files, but it when i try to open High Elves client files i get these error: "this package has an unknown signature



"
in the same time UTPT can view files of High Elves, but cannot extract any data from there