strange error during publishing

I was publishing my asp.net 2005 to my web site with up dates, but I kept getting runtime errors. with no details

so I created a new project(web page) added all the existing folders , pages(aspx and vb) then published no problem

what the heck is going on

also how do i create an error page so I can see the errors remotley?

Turn off the customErrors option in web.config of the website to check the detailed error message:

<customErrors mode="Off" />