Context is not the member of error

I have my website without layers now i am converting code to layers.
When i add some page design and try to generate its designer file be cliking rite on that page and clik on option
"Covert to web application"  it gives me error namespace cannot have space and sometimes it gives me error
System.exception was thrown error
My codefile name is correct and inherit name also correct  like below
 Source code is
<%@ Page Language="VB" AutoEventWireup ...