I Use D7, CKeditor v 1.16.7 and Media v 1.5.7, all other modules are up2date and the site itself works fine.
I don't recall any special change at the site that would avoid this module of working, yet suddenly it's upload button was removed from CKeditor's Full HTML palette (img 1) while appearing fine in Filtered HTML palette.
The CKeditor "Full HTML" profile's settings seems just fine (img 2).
Permissions are fine (I'm the Admin, img 3).
Rebuilding type information for media, didn't help.