The page contains markup that is not valid when attached to master page

解决方案：
把aspx里的comments拿掉就解决了，经过我的测试，成功解决。

原因：有些comments导致asp不能加载。

Solution:
Just remove the comments in aspx page which inherits masterpage .. this should work.

Reason : the comments may be asp style and will not get loaded.