[bkf0]

I ran into the same or similar issue. From my debug logs it appears to be an issue when login with ajax is also an active plugin…these are the two errors that repeat endlessly until there’s a server timeout:

[03-Oct-2015 22:00:33 UTC] PHP Warning:  current() expects parameter 1 to be array, null given in /var/www/html/_wp/wp-content/plugins/buddypress/bp-core/bp-core-template-loader.php on line 223
[03-Oct-2015 22:00:33 UTC] PHP Stack trace:
[03-Oct-2015 22:00:33 UTC] PHP   1. {main}() /var/www/html/_wp/wp-admin/plugins.php:0
[03-Oct-2015 22:00:33 UTC] PHP   2. require_once() /var/www/html/_wp/wp-admin/plugins.php:10
[03-Oct-2015 22:00:33 UTC] PHP   3. require_once() /var/www/html/_wp/wp-admin/admin.php:31
[03-Oct-2015 22:00:33 UTC] PHP   4. require_once() /var/www/html/_wp/wp-load.php:37
[03-Oct-2015 22:00:33 UTC] PHP   5. require_once() /var/www/html/_wp/wp-config.php:106
[03-Oct-2015 22:00:33 UTC] PHP   6. do_action() /var/www/html/_wp/wp-settings.php:353
[03-Oct-2015 22:00:33 UTC] PHP   7. call_user_func_array() /var/www/html/_wp/wp-includes/plugin.php:503
[03-Oct-2015 22:00:33 UTC] PHP   8. LoginWithAjax::init() /var/www/html/_wp/wp-includes/plugin.php:503
[03-Oct-2015 22:00:33 UTC] PHP   9. LoginWithAjax::getRegisterLink() /var/www/html/_wp/wp-content/plugins/login-with-ajax/login-with-ajax.php:91
[03-Oct-2015 22:00:33 UTC] PHP  10. bp_get_signup_page() /var/www/html/_wp/wp-content/plugins/login-with-ajax/login-with-ajax.php:270
[03-Oct-2015 22:00:33 UTC] PHP  11. bp_has_custom_signup_page() /var/www/html/_wp/wp-content/plugins/buddypress/bp-members/bp-members-template.php:1902
[03-Oct-2015 22:00:33 UTC] PHP  12. bp_locate_template() /var/www/html/_wp/wp-content/plugins/buddypress/bp-members/bp-members-template.php:1885
[03-Oct-2015 22:00:33 UTC] PHP  13. bp_get_template_stack() /var/www/html/_wp/wp-content/plugins/buddypress/bp-core/bp-core-template-loader.php:90
[03-Oct-2015 22:00:33 UTC] PHP  14. current() /var/www/html/_wp/wp-content/plugins/buddypress/bp-core/bp-core-template-loader.php:223
[03-Oct-2015 22:00:33 UTC] PHP Warning:  next() expects parameter 1 to be array, null given in /var/www/html/_wp/wp-content/plugins/buddypress/bp-core/bp-core-template-loader.php on line 229
[03-Oct-2015 22:00:33 UTC] PHP Stack trace:
[03-Oct-2015 22:00:33 UTC] PHP   1. {main}() /var/www/html/_wp/wp-admin/plugins.php:0
[03-Oct-2015 22:00:33 UTC] PHP   2. require_once() /var/www/html/_wp/wp-admin/plugins.php:10
[03-Oct-2015 22:00:33 UTC] PHP   3. require_once() /var/www/html/_wp/wp-admin/admin.php:31
[03-Oct-2015 22:00:33 UTC] PHP   4. require_once() /var/www/html/_wp/wp-load.php:37
[03-Oct-2015 22:00:33 UTC] PHP   5. require_once() /var/www/html/_wp/wp-config.php:106
[03-Oct-2015 22:00:33 UTC] PHP   6. do_action() /var/www/html/_wp/wp-settings.php:353
[03-Oct-2015 22:00:33 UTC] PHP   7. call_user_func_array() /var/www/html/_wp/wp-includes/plugin.php:503
[03-Oct-2015 22:00:33 UTC] PHP   8. LoginWithAjax::init() /var/www/html/_wp/wp-includes/plugin.php:503
[03-Oct-2015 22:00:33 UTC] PHP   9. LoginWithAjax::getRegisterLink() /var/www/html/_wp/wp-content/plugins/login-with-ajax/login-with-ajax.php:91
[03-Oct-2015 22:00:33 UTC] PHP  10. bp_get_signup_page() /var/www/html/_wp/wp-content/plugins/login-with-ajax/login-with-ajax.php:270
[03-Oct-2015 22:00:33 UTC] PHP  11. bp_has_custom_signup_page() /var/www/html/_wp/wp-content/plugins/buddypress/bp-members/bp-members-template.php:1902
[03-Oct-2015 22:00:33 UTC] PHP  12. bp_locate_template() /var/www/html/_wp/wp-content/plugins/buddypress/bp-members/bp-members-template.php:1885
[03-Oct-2015 22:00:33 UTC] PHP  13. bp_get_template_stack() /var/www/html/_wp/wp-content/plugins/buddypress/bp-core/bp-core-template-loader.php:90
[03-Oct-2015 22:00:33 UTC] PHP  14. next() /var/www/html/_wp/wp-content/plugins/buddypress/bp-core/bp-core-template-loader.php:229

Simple fix is to deactivate login with ajax, then deactivate buddypress, then activate login with ajax.

This error might also present itself with other plugins/themes that have custom signup pages.