ExpressionEngine control panel shows raw source

Question

this is happening randomly, but when I go to my login page, it sometimes just shows

on other occasions, I tried to view the filemanager but got a page with

{"rows":[{"file_id":"686","title":"logo220.png","file_name":"<a href=\"http:\/\/www.xyz.org\/images\/uploads\/emails\/logo220.png\" class=\"less_important_link overlay\" id=\"img_logo220png\" rel=\"#overlay\">logo220.png<\/a>","mime_type":"image\/png","upload_location_name":"emails","upload_date":"2014-10-20 03:43 PM","_actions":"<a href=\"loginURL.php?

it doesn't happen all the time so I'm a bit stumped.

does anyone have experience with that?

EDIT: it's happening on a couple of our sites now (on mediatemple's grid service) and sometimes, the login screen just shows "C=login"

Answer 1

turns out it was an issue related to the host: media temple offers different versions of PHP and the 'fastCGI' version can cause these issues. I switched to the 'stable' version and the issue disappeared.

Answer 2

Check the integrity of your installation. It is likely that some files in themes folder are missing or corrupt (the best thing is to re-upload the whole of CMS files, making sure to not overwrite configs of course)