启用插件显示空白，debug报错如下
[27-Oct-2017 13:56:00 UTC] WordPress数据库查询
CREATE TABLE IF NOT EXISTS `` (
`id` bigint(20) NOT NULL auto_increment,
`sender` bigint(20) NOT NULL,
`receiver` bigint(20) NOT NULL,
`content` longtext NOT NULL,
`status` int(1) NOT NULL,
`time` int(10) NOT NULL,
PRIMARY KEY (`id`)
) DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci时发生Incorrect table name \'\'错误，这是由activate_plugin, do_action(\'activate_wpjam-basic/wpjam-basic.php\'), WP_Hook->do_action, WP_Hook->apply_filters, wpjam_basic_activation, dbDelta查询的。