Help me please!!

i've bought my nephew a sky quad plus v2. It's been flying fine until now..all the lights are flashing on the drone and controller but will not take off..(1 leg is missing)..can someone help please

Thanks

By losing the leg its no longer level when you turn it on so the fc is reading thats its level when it really isnt. In other words make sure its level when you turn it on. Also make sure your batteries are filly charges. Flashing lights are a sign theyre not, depending on the quad.