[mwheelermindbox]

I am using WordPress 4.8 multisite and noticed a bug in bbPress 2.5.12 and 2.5.13 (possibly older versions as well) with PHP 7.1.6.

Lines 1798-1805 of includes/forum/functions.php is

// Default to public status
if (empty( $post_stati ) ) {
	$post_stati[] = bbp_get_public_status_id();

// Split the status string
} elseif ( is_string( $post_stati ) ) {
	$post_stati = explode( ',', $post_stati );
}

For me $post_stati looks to be an empty string so the if is evaluating to true and the next line is failing with this error:

Fatal error: Uncaught Error: [] operator not supported for strings in /srv/www/tilth.org/current/web/app/plugins/bbpress/includes/forums/functions.php on line 1800

Changing line 1799 to:

if (is_array( $post_stati) && empty( $post_stati ) ) {

looks to fix the error.

Perhaps adding a line inside the conditional of

$post_stati = array();

is a better fix.