It's not Logonstudio that is not working. It's the skin you have applied. There may be a bug in the coding of the logon skin you have used. What skin is it anyway?
While you are seeing that error, you don't need to force restart you system. you just need to click OK for about 10 times and then your computer brings you to the default Win2K logon. Use that to log in back to your account, and choose another logon screen or you may disable logonstudio for the meantime.
