my full log, using 1.8.9 and spongeforge 1722
mods: pixelmon 4.2.7, worldedit 1.8.9.6.1.1, griefprevention 1.8.9 2.0.0.5.9
Startup log where it end with a crash
http://hastebin.com/itesahugos.vbs

I cant use a new sponge version because i am using pixelmon (that is stable and only compatile with 1722 forge, yes there are some "beta version" that use a more recent spongeforge. So there is no way for use pex with this version?

I don't think PEX 2.x is for old Minecraft servers. Zml will have more information for you.

The issue here is that you're running a massively outdated version of sponge. Run the latest sponge and the version of forge listed there.