[pinkhare]

Notice: bbp_setup_current_user was called incorrectly. The current user is being initialized without using $wp->init().

I have been getting this message from 2 years ago and I have been reading all the related posts and Q&As from time to time, but it seems that this problem is not resolved yet. I sure that this is a bbPress issue or the issue of Customize template/function for wordpress. Because I have tested with no plugin, so it’s not the case of conflicting plugin and I used WordPress default themes(Twenty Fourteen & Twenty Fifteen).
My wordpress version is 4.1 & my bbpress version is 2.5.4.

The most important thing is that message is only shown on the admin’s ‘Customize‘ page.
I’m developing my own theme, so I want to fix it without disabling WP_DEBUG config.

[Robin W]

As you no doubt already know, this is just a warning message, and bbpress say it is an issue with wordpress, and are waiting for wordpress to fix. Also as you know (but for others reading this), turning off debug fixes this.

If you want it to disappear whilst you are developing (and so need debug on), then go to

wp-content/plugins/bbpress/includes/core/sub-actions.php

and comment out/change line 147

_doing_it_wrong( __FUNCTION__, __( 'The current user is being initialized without using $wp->init().', 'bbpress' ), '2.3' );

to

//_doing_it_wrong( __FUNCTION__, __( 'The current user is being initialized without using $wp->init().', 'bbpress' ), '2.3' );

and change back after developing as well as turning debug off for the production environment

[auludag]

this helped me as well. Thanks Robin W.