Server randomly kicks off players

[Vasuvo]

I've been running a server for a few friends recently, and there's a bug where the server seems to kick people off randomly, with no apparent pattern. It happens to everyone on the server, no matter what they're doing, although they're able to reconnect immediately after.

Here's what it says from the server console (Vasuvo is my username);

 

Edited April 20, 2015 by Vasuvo