Call current_user_can after init()

Running buddypress? Are you getting a debug notice like this:

The current user is being initialized without using $wp->init()

and you cannot figure out where it is coming from ?

Most likely one of your plugins is calling a user related wordpress function a bit early (see wordpress action sequence).   You could try deactivating them until the debug message goes away.  The last plugin deactivated will be it.  Let the developer know because his/her code may not be quite working the way it was intended to.

eg: current_user_can()  or possibly  wp_set_current_user()

These need to be used after the init action.  The plugin or theme might have something like

add_action ('plugins_loaded', 'some_function');

The action should be added later, when the current user has been initialised.

add_action ('init', 'some_function');