High sierra bootable usb

[hima4all]

Hello, my macbook is not booting anymore. I have only a linux mint so i found your tool which will make bootable usb to install a fresh mac osx again. the problem is when i choose high sierra it download only the security update. So i download it manually using gibmacos and tried to run the other functions in your script but i am getting the following error in the extraction part function unpackhfs Path = InstallAssistantAuto.pkg Type = Xar WARNINGS: There are data after the end of archive

do you have a clue how to solve this

Best Regards Ibrahim