Most problems with the Flux WiFi smart bulb can be fixed with a quick factory reset. You can do that by following these steps:
1. Power on the bulb and wait for it to turn on.
2. Wait 1-3 seconds and power off the bulb
3. Repeat the above two steps 4 times.
On the fourth attempt, the bulb will enter into a strobe mode. After about 20 seconds, the bulb will turn bright white, and the reset is complete. At this point, you should be able to see the bulb's wifi endpoint (shows up as LEDNetxxx) from your phone's wifi settings. You can connect to this, open the app and go through the setup process to pair the bulb with your home wireless network, and you should be all set.