asp.net encrypt querystring c# + 404 - File or directory not found.

Hi, i created a site using asp.net C#,
it's working fine in my local iis and in visual studio 2010, but in the host i'm getting error as  Server Error 404 - File or directory not found. The resource you are looking for might have been removed, had its name changed, or is temporarily unavailable.


this is my site url, this is working if the query string is removed
http://times.com/regpage.aspx?EmailID=7SKkxx6XF2xz3kk/pdFCjWniWjdw/r4UA38313WUmbWyrIeNPjdZlfcF5jrYRLS9CFFbBdGc6oHDaoCFA8vPfg==

using the  encrypted string i ll get the values in the  page load.
 
i don't know where the problem is the path is correct also i checked the spelling, could any one help how to fix the issue.

Thanks in advance

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