Does things differently??

[Roy Dennis]

Try this. First off remove all folders from the build database list of folders so that no file paths are listed.

Then press the rebuild database button and it should build an empty database.

Now check the folder you want to add still contains your KMA files, if it doesn't then you may find they have been quarantined due to duplicated files found.
If they are still intact, then Add your kma folder to the list of folders, can't remember if 5.08 rebuilds as you add folders but if it does you should see a dialog confirming the amount added. If not press the rebuild button again.

Let us know if it works now.