None of the Themes rendering on drupal website

Today I had a weird problem with one of my drupal websites. I did not make any changes to this website and it has been running for some years. Suddenly my theme is completely broken and its not appearing either on website or admin pages

  • I tried to switch to Garland theme but didnt work
  • I cleared my caches still didnt work
  • I checked my website directories to see if any files were deleted, but every thing was fine over there too.
  • I updated drupal and my modules to latest version but still nothing.

Then I realized by browsing on web that I have enabled Performance management and compress css, Javacript etc.

I immidiately went to Site configuration >> Performance and disabled everything there and Bingo my theme was back.

The issue was due to the fact that cached files were removed hence the theme was not rendering and since I had enabled all caching , none of the newer themes would render since it would continue to look for cache to load the theme.