Here is the thing : when you deploy lightswitch app to a windows 2003 and iis6, if your app's name is not English, the forms authentication is not work because the forms name is the app's name and iis6 seems not support this. So I waste two days to find out it and now I have to change web.config every time when I publish it.the issue like that: <authentication mode="Forms"> <forms name="一二三四五" /> </authentication>it not work on iis6/windows2003