Comment 1 for bug 1356563

I was able to replicate the issue. Here's the underlying error:

[WAR] 9c (lib/mahara.php:1577) call_user_func_array() expects parameter 1 to be a valid callback, class 'PluginModuleSample' does not have a method 'menu_items'
Call stack (most recent first):

    log_message("call_user_func_array() expects parameter 1 to be a...", 8, true, true, "/home/aaronw/www/mahara/htdocs/lib/mahara.php", 1577) at /home/aaronw/www/mahara/htdocs/lib/errors.php:439
    error(2, "call_user_func_array() expects parameter 1 to be a...", "/home/aaronw/www/mahara/htdocs/lib/mahara.php", 1577, array(size 3)) at Unknown:0
    call_user_func_array(array(size 2), array(size 0)) at /home/aaronw/www/mahara/htdocs/lib/mahara.php:1577
    call_static_method("PluginModuleSample", "menu_items") at /home/aaronw/www/mahara/htdocs/lib/web.php:2696
    right_nav() at /home/aaronw/www/mahara/htdocs/lib/web.php:516
    smarty() at /home/aaronw/www/mahara/htdocs/admin/index.php:65

[WAR] 9c (lib/web.php:2697) array_merge(): Argument #2 is not an array
Call stack (most recent first):

    log_message("array_merge(): Argument #2 is not an array", 8, true, true, "/home/aaronw/www/mahara/htdocs/lib/web.php", 2697) at /home/aaronw/www/mahara/htdocs/lib/errors.php:439
    error(2, "array_merge(): Argument #2 is not an array", "/home/aaronw/www/mahara/htdocs/lib/web.php", 2697, array(size 8)) at Unknown:0
    array_merge(array(size 12), null) at /home/aaronw/www/mahara/htdocs/lib/web.php:2697
    right_nav() at /home/aaronw/www/mahara/htdocs/lib/web.php:516
    smarty() at /home/aaronw/www/mahara/htdocs/admin/index.php:65