Yes, this bug seems to be the problem.
As a quick fix for linux change to you Planeshift program directory and do that:touch errorlog.txt
sudo chmod +w errorlog.txtThis made me start the game.
Since I don't really know how to do that in Windows there is also another option: play as root/Admin, but I don't recommend that. This problem will be fixed soon (maybe even before the server is online) and then it should be possible to play as a normal user, even on Windows.
PS:
what it does: touch creates the file if it doesn't exist and chmod makes it writable for any user.