CSS is not applying on the pages and only random content is visible while previewing the page after developing it, is this is due to some changes in JVM or any other issues. How can I correct it?? please suggest me on this..
You'll have to do a lot more debugging on your end to find the source of the error. Without access to your server, that problem description is not enough to really suggest anything at all.
In your tpl, is the css absolute or relative?
i.e.
absolute - /root/css/file.css
relative - ../css/file.css