Statistics (Graph Stats)

I installed the block, but the diagram does not appear. Does someone know why this could be happening? I have Moodle 2.4 version

Graph Stats gives these errors in Moodle 2.4dev:
Notice: Undefined property: stdClass::$daysnb in C:\M24dev\server\moodle\blocks\graph_stats\block_graph_stats.php on line 72
Notice: Undefined property: stdClass::$engine in C:\M24dev\server\moodle\blocks\graph_stats\block_graph_stats.php on line 79
Capability "coursereport/log:view" was not found! This has to be fixed in code.
line 377 of \lib\accesslib.php: call to debugging()
line 97 of \blocks\graph_stats\block_graph_stats.php: call to has_capability()
line 284 of \blocks\moodleblock.class.php: call to block_graph_stats->get_content()
line 232 of \blocks\moodleblock.class.php: call to block_base->formatted_contents()
line 953 of \lib\blocklib.php: call to block_base->get_content_for_output()
line 1005 of \lib\blocklib.php: call to block_manager->create_block_contents()
line 353 of \lib\blocklib.php: call to block_manager->ensure_content_created()
line 6 of \theme\base\layout\general.php: call to block_manager->region_has_content()
line 793 of \lib\outputrenderers.php: call to include()
line 740 of \lib\outputrenderers.php: call to core_renderer->render_page_layout()
line 1416 of \lib\blocklib.php: call to core_renderer->header()
line 1096 of \lib\blocklib.php: call to block_manager->process_url_edit()
line 1376 of \lib\pagelib.php: call to block_manager->process_url_actions()
line 829 of \lib\pagelib.php: call to moodle_page->starting_output()
line 735 of \lib\outputrenderers.php: call to moodle_page->set_state()
line ? of unknownfile: call to core_renderer->header()
line 1445 of \lib\setuplib.php: call to call_user_func_array()
line 98 of \index.php: call to bootstrap_renderer->__call()
line 98 of \index.php: call to bootstrap_renderer->header()
The block graph_stats does not define the standard capability block/graph_stats:addinstance
line 597 of \blocks\moodleblock.class.php: call to debugging()
line 575 of \blocks\moodleblock.class.php: call to block_base->has_add_block_capability()
line 1082 of \lib\blocklib.php: call to block_base->user_can_addto()
line 1043 of \lib\blocklib.php: call to block_manager->user_can_delete_block()
line 248 of \blocks\moodleblock.class.php: call to block_manager->edit_controls()
line 953 of \lib\blocklib.php: call to block_base->get_content_for_output()
line 1005 of \lib\blocklib.php: call to block_manager->create_block_contents()
line 353 of \lib\blocklib.php: call to block_manager->ensure_content_created()
line 6 of \theme\base\layout\general.php: call to block_manager->region_has_content()
line 793 of \lib\outputrenderers.php: call to include()
line 740 of \lib\outputrenderers.php: call to core_renderer->render_page_layout()
line 1416 of \lib\blocklib.php: call to core_renderer->header()
line 1096 of \lib\blocklib.php: call to block_manager->process_url_edit()
line 1376 of \lib\pagelib.php: call to block_manager->process_url_actions()
line 829 of \lib\pagelib.php: call to moodle_page->starting_output()
line 735 of \lib\outputrenderers.php: call to moodle_page->set_state()
line ? of unknownfile: call to core_renderer->header()
line 1445 of \lib\setuplib.php: call to call_user_func_array()
line 98 of \index.php: call to bootstrap_renderer->__call()
line 98 of \index.php: call to bootstrap_renderer->header()

Graph Stats is working fine in Moodle 2.3.3