Friend getting kicked of the server

Hello , i have a modded server on 1.10.2 version and my problem is that while i can play normally my friend keeps gettings kicked every 2-3 minutes.Here is the log https://mclo.gs/bQb4d7q and also the server is cracked.

Yes is does , sometimes i have to restart because my friend gets kicked and can't join back again.

Well i created this server a while ago and my friend only joined a few days ago and the problem started immediately.I never had any issues while i was playing alone so i was thinking that the world might be corrupted but then wouldn't i have the same problem?

We haven't tried that but i noticed that when the disconnect happens i see a red X on his signal so it could just be his connection , so i will leave it for now no need to take more of your time.