How odd. There should be a new DB table – that’s why the plugin is displaying “Sorry, no data so far”, the migration process didn’t occur or failed for some reason.
In the meanwhile, you can either downgrade to 2.3.7, or run the following queries manually via phpmyadmin to create the new table and migrate the data:
CREATE TABLE wp_popularpostssummary (
ID bigint(20) NOT NULL AUTO_INCREMENT,
postid bigint(20) NOT NULL,
pageviews bigint(20) NOT NULL DEFAULT 1,
view_date date NOT NULL DEFAULT '0000-00-00',
last_viewed datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
PRIMARY KEY (ID),
UNIQUE KEY ID_date (postid,view_date),
KEY postid (postid),
KEY last_viewed (last_viewed)
);
INSERT INTO wp_popularpostssummary (postid, pageviews, view_date, last_viewed)
SELECT id, pageviews, day_no_time, day
FROM wp_popularpostsdatacache
GROUP BY day_no_time, id
ORDER BY day_no_time DESC;
RENAME TABLE wp_popularpostsdatacache TO wp_popularpostsdatacache_backup;
…. and the version changes the the very nice layout that I had (Use custom HTML Markup)
This should not have happened. Are you sure the custom HTML has been changed and that it’s not a CSS issue?