Again you don't state which version of Hoster you are using, you can find this from the help menu by selecting about Hoster.
Generally if you enter the same Brand and Disc ID that you used when you originally entered that disk it should appear correct after hitting the search Local database button providing that you originally imported it by this method.
After entering your Brand which must be the same as when you originally entered it, if you click on the drop down arrow for Disc Id you should see a list of all the Disc id's both that you entered yourself and the ones that come with Hosters own database with the version of Hoster you had at the time.
When you use this drop down box do you see a list of Disc id ?
If not it seems something has gone amiss with your database
If it's because you can't remember the Disc Id you used, as a suggestion you can try this: From the Tools menu select Edit Songs, then search for one of the titles on that disc then you should be able to find the brand and disk id associated with that disc then go back to the import CD dialog and see if entering the info you found there still gives you unknown results.
For further help please state your versions of Windows & Hoster.