I was having the exact same issue as Floyd Jane (and others, apparently), and nothing suggested above or in all the relevant threads seemed to help. On a whim based on Andrew's post, I installed the 414 patch, and that seems to have solved it. I say "whim," because I got BB2015 on the USB drive and it has the label "UP414" pasted on it! Pretty sure I had the proper "Instruments" subfolder in the path designated in the ST prefs - the default, btw - before I ran the patch, so I'm thinking the drive was mislabeled.

Hope this saves someone else a bit of time. -Ron

Originally Posted By: Andrew - PG Music
We update some HiQ files in the BB2015 patch (this mainly fixes some small tuning issues). The HiQ instruments rely on files in the bb\DX Settings folder, and also in the IK Multimedia folder which is usually in Program Files. People who have manually copied their IK Multimedia (Instruments) folder to a different location after installing it, might end up with those files not being updated by the patch.

We'll try to make this work better in the next patch. If anyone has this problem in the meantime, you could copy the Instruments folder back to the default location (i.e. "C:\Program Files (x86)\IK Multimedia\Instruments" or "C:\Program Files (x86)\IK Multimedia\SampleTank 2.5\Instruments") then install the patch again.