gistfile1.txt

Coding error detected, it must be fixed by a programmer: Trying to reference an unknown block region side-pre 

Debug info:
Error code: codingerror
Stack trace:

    line 889 of /lib/blocklib.php: coding_exception thrown
    line 989 of /lib/blocklib.php: call to block_manager->check_region_is_known()
    line 1002 of /lib/blocklib.php: call to block_manager->ensure_instances_exist()
    line 315 of /lib/blocklib.php: call to block_manager->ensure_content_created()
    line 1370 of /lib/outputrenderers.php: call to block_manager->get_content_for_region()
    line 3202 of /lib/outputrenderers.php: call to core_renderer->blocks_for_region()
    line 96 of /theme/clean/layout/columns3.php: call to core_renderer->blocks()
    line 866 of /lib/outputrenderers.php: call to include()
    line 796 of /lib/outputrenderers.php: call to core_renderer->render_page_layout()
    line 101 of /index.php: call to core_renderer->header()