Paper: Crash error everytime someone joines happends with multiple people.

[StefvanderMeer]

Crash, Stacktrace

Link/paste of stack trace

Console LOG:
https://pastebin.com/13EGVhBe
Crash Report:
https://pastebin.com/LiACpjBD
Startup LOG:(if needed)
https://pastebin.com/7f8rUuAn

Plugin list:

http://imgur.com/a/yoKuV
http://imgur.com/a/ylbgS
xD i have alot

Actions to reproduce (if known):

When a player joins the full server will crash. I don't really know why it just gives me those errors. When I teleported to the last coordinates of that player it crashed the server too. I had to delete my player file to fix the problem that I can join again.

It still happens to a lot of players and I want to fix this.

Paper build number:

http://imgur.com/a/GEQfV

[zachbr]

We don't support 1.8.8 though it appears your map is corrupt.

[DemonWav]

Plugin list:

http://imgur.com/a/yoKuV
http://imgur.com/a/ylbgS
xD i have alot