I just tried installing this plug in as well and I get the same 500 server error. Looking at the php error logs I get the following entries when I try to access the WP_Admin site after activating the plugin…
[29-Aug-2012 16:42:27] WordPress database error Unknown column ‘event_notes’ in ‘wp_em_events’ for query ALTER TABLE wp_em_events CHANGE event_notes post_content longtext NULL DEFAULT NULL made by require_once(‘wp-admin/admin.php’), require_once(‘wp-load.php’), require_once(‘wp-config.php’), require_once(‘wp-settings.php’), do_action(‘init’), call_user_func_array, em_init, em_install, em_create_events_table
[29-Aug-2012 16:42:27] WordPress database error Unknown column ‘location_description’ in ‘wp_em_locations’ for query ALTER TABLE wp_em_locations CHANGE location_description post_content longtext NULL DEFAULT NULL made by require_once(‘wp-admin/admin.php’), require_once(‘wp-load.php’), require_once(‘wp-config.php’), require_once(‘wp-settings.php’), do_action(‘init’), call_user_func_array, em_init, em_install, em_create_locations_table
Any help would be nice. Looking at the plugin demo, etc. I think this is just what I am looking for, but if I can’t get it working I am SOL.