NullPointerException in onSend for 1.13.1

Version Server: This server is running CraftBukkit version git-Spigot-f6a273b-db10914 (MC: 1.13.1) (Implementing API version 1.13.1-R0.1-SNAPSHOT)

Issue: in SentPacket trigger a error with version.

Log: https://hastebin.com/ezenaloriv.shell