ًWhy didn't you tell me before Thom

Ok, so you can run the game after clicking away the error. If you do not want the error at all (or in case of more fatal problems in the future) do the following:
1. in the directory planeshift is intalled in, make a new text file named 'startps.bat' (or any other name.bat)
2. In this file (right-click edit) put the following (and save):
set CRYSTAL=.
psclient
3. start the game double clicking this batch file.
4. enjoy an errorless ps
Ok, for 4 there may be some more steps, but at least it is one error less
