I recently built the blog http://www.spectrometer-blog.com with WP 3.8 and
Customizr 3.15
When the installation is fresh the RSS feed works but as I develop the site, the RSS faulters and now I have "feed no longer exists"
I use the a few standard plugins like SEO all in one, Google analytics, and Visual Composer.
This seems to be a frequent problem but I have never seen a robust solution posted.