By changing WordPress site url , unable to make changes and preview

Hi there,

I have an blog site on wordpress on subdomain blog.vanitycask.com then I decided to make it in subfolder of site i.e. www.vanitycask.com/vanitybuzz (the site is running on Ruby on Rails framework). So I used reverse proxy and made changes in the wordpress site url from "blog.vanitycask.com" to "www.vanitycask.com/vanitybuzz" now everything is working as desired except the customization and editing previews. Wordpress admin dashbord showing me "Non-existent changeset UUID." when I tried customisation on the site, also not showing any previews.

please help me what should be done now I am stuck too badly.