Smartthings lost connection to Philips Hue Bridge

Major platform problems yesterday and today are making it pretty difficult to troubleshoot anything right now:

I think you’ll probably have to wait until that all settles down and then check and see if the Hue is still having problems.

As far as reliability/stability, that is not SmartThings’ strong suit. It is a very flexible, powerful low-cost platform, but they make changes all the time, and things can get a little rocky.

http://thingsthataresmart.wiki/index.php?title=Bug:_First_Reports

If stability is your top priority, you may want to look at other systems instead. Every system has pros and cons, and different ones will work for different people.