I found this problem in my server: http://hastebin.com/didesizaga.coffee when I start my server it happens
info:
Using version: PermissionsEx 1.20.2
Server version: 1.5.2
Jar: Spigot 1.5.2

please help me!

Step 1: Stop using a version of PEX and MC that is multiple years old. We don't support anything older than 1.7.10/PEX 1.22.10 or 1.8.9/PEX 1.23.4

i like older versions u.u