Akshay Sura recently installed XBlog and found a problem on Sitecore 8.2 Update 5. He found that the database type had changed from Sitecore.Data.Database to Sitecore.Data.DefaultDatabase . I dug through the older versions and found that this was present in all Sitecore 8.2 Updates.
To manually fix this problem please navigate to App_Config/Include/XBlog.Sitecore.Buckets.config . There are three references you will want to change:
I have also submitted a package to the Sitecore Marketplace to patch this. This should be available this week, pending review. As always please reach out to me if you have any questions. The best form of contact is via my Twitter Account.