Disconnecting a specific person from server

Whenever I create a server (not dedicated just using the in game client) I have a specific friend that constantly gets disconnected. This isn't an issue with anybody else I've played with on my server and when we've joined other people's servers there has been no issues.  Additionally when I connect to his server I get disconnected from it. The length of time before a disconnect can vary from after just a few minutes to 30 minutes or more but it still happens every session.

We usually use mods but I tried disabling and it's still an issue.

We play other games that take direct connections to the other persons computer and have never had an issue.

I'm on Mac OS and he uses a PC. Any ideas on the issue here? Is there any logs I can upload that might help? I'll be able to get them later this evening when I'm home.

Thanks!

Edit: I wasn't able to find the server log, I found my own client logs though. I put a few of them in as well as my friend's log (Zatara client_log). I looked for server logs but couldn't find any. Hope this helps.

client_log.txt

chat_log.txt

client_log_2016-09-14-20-31-48.txt

zatara client_log.txt