Salut Duke ça va? I got this error tonight with 3.8.7, the first time I got this particular error in three years with LW.... I think this is an os x installer problem. I tried to fix it by reparing permissions and restarting the computer, but no luck.
Because I'm power user, I have other partitions (because they have some use in some cases
), and so I installed it on an other partition, then I dragged the LW folder in the applications one in my main os x partition and it works as great as usual. Hope this is helpful to you.
Bonne chance mec!