I upgraded today from 3.0.5 (I think!) to 3.6 and what I got is this -
The site itself (visitor part) works fine (I think so, but haven't checked every plugin yet).
But at the admin part - I have no menu on the left side. I see all typical console stuff all right in the middle part, but where was menu - like left side bar - now is just an empty white space.
The URLs of admin sections work fine - like if I type - http://www.marcool.ru/wp-admin/plugins.php - into the URL input of my browser - I get to the plugin sections all fine, but again, with no menu on the left. (but this is totally inconvenient to 'live with')
This is the screenshot if interested
Anyone had this? Any cure?