I host a small server for my friends and me. It has worked well for me, until recently. My one friend, who has very bad internet, has been kicked by the server for "flying while flying is disabled." Flying is not enabled, and we are all in survival mode, but he gets kicked for this. Nobody else has this problem on my server except him. He has no mods or plugins on his client. Like I said before he has a slow/bad connection, so the only thing I can think would be happening is he is lagging and is thought to be flying by the server. I don't know if there is any way to fix this, and I would like to keep flying disabled. Thanks for any help if you have some.
It may also be worth noting that he frequently says he is "in a wall." When I go to his location, he is appears to be standing above the ground, though he still claims to be "in a wall." He can be shot, punched, ECT. while he is in this state. This sounds like internet lag to me, but I'm not sure.
No, the "allow flying" option in the config is there to prevent people who have flyhacks or flying cheats of the sort from flying. If flying isn't in a mod or a plugin that the server has, it'll kick a player for being in the air without touching the ground after a few seconds of staying there. Turning on flying in the config just disables being kicked for flying, it won't let everyone fly in survival mode. You need a plugin, mod, or creative mode to fly.
If lag is a problem for you, check where your server is hosted and make sure he isn't lagging because his ping is really high. You can see your ping by hovering over the green bars to the right of a minecraft server and should come up with something along the lines of, 67MS, whatever there number may be determines the speed at which your server and there internet send and receive packets.
Less than 50MS = Amazing, if you lag with 50MS or less ping contact your server host.
51MS - 150MS = Average, may have few lag spikes but should not effect gameplay much.
151MS - 200MS = Getting poor, if you have this high of ping you should be lagging a little bit or a lot, means your far away from where the server is hosted.
201MS+ = Just don't play on the server or go restart your router.
Check your internet speeds at www.speedtest.net to make sure your internet isn't too slow for the game. This should help if any other players lag on your server. They can also on Windows, open Command Prompt (CMD) and type ping (your server IP) then hit enter. Once its done it should say around the lines of "average ping/MS" that can also help determine if the lag is your player or the hosting company.