For the AudioBox VSL series - you'll want to read this tech support update posted in 2015.
For StudioLive FireWire Mixer products, 1642, 2442, 1602
Apple has decided to discontinue support for 32-Bit in iOS11, the updates to Apples developer library, XCode no longer support older Mac OS running 32-bit, this required building SL Remote and QMix for newer versions of iOS. That also meant changes to UC 1.7 which makes the new minimum OS for UC 1.7 move up to 10.9 instead of what it was previously.
You won't lose VSL for StudioLive in UC 1.7. However if you want to continue to use the older version of iOS applications for SL Remote and QMix, you will need to roll back to a previous version provided you have made a back up on your iTunes (locally). Then if you choose to use the older Mac OS X with the version of UC you were running previously you can continue to do so.
This 3rd party blog details how you can roll back your applications to older versions.