When i change my permalink into /%category%/%postname%/ it became 404 not Found. and Google can't crawl my site what should i do? if DP has already have the thread about this.please tell me i want to know how to handle it thanks
What became 404 not found? The index? All of the pages? I take it you are referring to Wordpress? If you want me to have a look at it shoot me a PM with the site url and the login details.
Check to make sure that the file the URL refers to exists and has correct file permissions. This error is usually caused when a file/folder doesn't have correct permissions, making it inaccessible to the web server.