Apologies for the long post, but I've been playing with these things for well around a year and a half and have had to set them up at several places so I've learned a few tricks and had my fair share of hair pulled out - too bad it won't grow back anymore... dog-gone male-pattern-baldness... Also, because I don't know your level of tech experience, I'm going to try to keep terminology lay and simple. I'll include definitions and descriptions where possible to help out. also, sorry for any misspellings, grammar issues, and/or casing of letters. I'm typing this from my phone because i cannot fall asleep...
Back when my lights worked, i had to try the following steps: try them in order and only go to the next one if the current one is not giving you any results and doesn't fix your problem:
update the light (firmware) and try again. there's usually an option when you try to claim it or in the menu button there's an option to update ALL bulbs firmware... caution as the more bulbs you have connected and powered, the longer you'd still take... my suggestion is to use suggestion S1 for setting up all new bulbs and then putting them where you like afterwards...
flick the light switch (or power switch) off for about 10-30 seconds, then then flip it back on. close the app (push the phone button to show running apps and swipe or tap the x to close the app officially). that flushes the app and forces it to refresh since the app is missing a refresh button and doesn't always update. reopen the app and try to reclaim it. if that fails, try to close the app completely again and repeat this step again...
tell it to 'delete' the light,close the app completely (like step 2) and start over...
only do this if steps 1-3 fail and you don't have very many lights already successfully connected from the same switch. check out Suggestions below (S1 in particular) for help with making reset easier. To reset your bulb to default or original firmware version and settings, click the light switch for the relay your bad bulb is on 5 times (do off-then-on 5 times) fairly quickly. this will reset ALL bulbs in that relay, which will undo any work completed on bulbs anyway for that relay. For example, if you have 3 lights that are working in your app and 1 that isn't working that all turn off if you turn one light switch off, then all 4 are on the same relay. Suggestion S1 gives you a trick to reset and configure 1 bulb at a time without messing up working bulbs.
is possible that your light is messed up, and/or your router is upset or maybe you need to get a wifi booster so your bulb can find and reach your router. check the help pages in the app. it's plausible that your router is not dyeing enough and/or new enough. it could have a limited number of devices it can read/handle before it stops leasing new internal IP addresses to your extra devices/light-bulbs. check your manual for your router and/or the forums or support for your router. if the router is being rented from your ISP (Internet service provider: exa Comcast, Suddenlink, AOL, etc), then you may need to talk to your ISP service first because they will know more about your router limitations and can walk you thru Avent your router settings.
S1. if you have many bulbs connected (more than 1 or 2) successfully and in the same relay as a misbehaving bulb, then it may be worthwhile to take the bad bulb out from that switch relay and put on its own relay for easier resets. a lower level light outlet, team with lights that's not on the ceiling, or an expensive portable lamp that has similar voltage and amperage requirements to match the place where your light will be going.
S2. i found that if i was connected to my wireless router using the 5ghz frequency and my lights are only seeing the 2ghz frequency, then it helped to wifi into the 2ghz frequency on my phone first (or visa versa of the light connects to the 5ghz frequency)
S3. When setting up bulbs, adding them, OR trying to claim them, I found that the process took less time and worked more often when i doesn't try to change any setting about the bulb (name or group) EXCEPT the ssid (ie. wifi router) to connect to, password, and home to sign it. Once that is done, and the light works, THEN you can change the name and group safely without having to redo it 100 times. write down the name of the bulb if you want to change names and groups at the same time for a lot of bulbs OR then off ALL bulbs via the app and turn on only the one you want to name and put in a group... this way, you know which one you are dealing with and don't need paper and writing utensil...
I hope this helps you. currently, most of my lights do not work with the app so I'm working on an app that tries to only talk to them from the LAN (your local network that lets your computers, SMART TVs, and devices to talk to eachother) so I can see if my problem is related just to the app or is also firmware related.
Cheers and the best of luck to you,