Philips Hue FIX: HomeKit bridge already paired by another user error
If you have a Philips Hue system and have tried setting it up with HomeKit you may have run into the dreaded "HomeKit enabled bridge has already been paired by another user" error when trying to setup Siri voice control (give HomeKit access to your Hue bridge) from within the Philips Hue app.
Philips has a way to reset just the HomeKit portion of your Hue Bridge without losing all of your hard-setup scenes or lights. The fix essentially sends a JSON command to your bridge. Because it's such a widespread error they have a dedicated page inside of Hue Labs that applies the fix for you.
All you have to do is pair your Bridge to the Hue Labs website (this is a push-button affair: on the website and on your bridge). Then you can give Siri access to your Hue Bridge like it's supposed to work.
Link discussing the issue: Bridge already paired by another user - fix needed | Philips Hue API
Hue Labs fix link: HueLabs | Reset Siri voice control