Don't open [font=courier new]SweetHome3D-linux-x64[/font] with a text editor but run it as a script using this tip or in a Terminal window.
Depending on how you copied files on your USB stick, you may also have to reset execution rights on [font=courier new]SweetHome3D-linux-x64[/font] and [font=courier new]jre/linux/x64/jre8/bin/java[/font] files.