Eureka
Ok i opened painfull "as admin"
Then "zlib.dll not found"
So i downloaded it here :
http://www.dll-files.com/dllindex/dll-files.shtml?zlib
Then it eally works
So i extracted "Tweaks.lua"
I modified gravity
But i cant repack it, I try some different things, nothing works
I replaced lscripts.pak in Data (i maked a copy-back of course)
And always it says me "Tweaks not found, ... not found, not ound .. etc ...abandon ignore tryagain"
Do you know what is the problem ? thanks