On my network (bungeecord + spigot's), when users change switch the node/server, most of the time this error appears in spigot console:

https://hastebin.com/huworewove.md

On pastebin:

http://pastebin.com/yryzXWSj

i try runing a update to all plugins, i put the spigot's on the last release of 1.10.2 and the errors continue appears. i try to disable all spigot plugins and the error continued to appear...

My network:
Last release 1.10.2 spigot.
Last release of bungeecord.
All plugins updated.
Running on java 8.
Linux Debian 8

(My english is horrible, sorry)