When connected in Drupal (the problem does NOT happen when logged out), I see a strange � character.
The character seem to break Ajax calls all over the admin (I get an alert, with code 200, and the result of the Ajax request). I get the error when editing views, adding some contents, etc. Anything that requires Ajax.
The character also appears on every pages of the website, but only if I'm logged in Drupal. Otherwise, it doesn't appear.
I figured, the problem can't be in a file, or it would happen when I'm logged out too ?
Is there some files that are only called when logged in ?