Server random crashes, cant figure it out HALP

Cant figure out what is going on but i am having these random crashes and cannot figure out why, have pasted the crash report to the link provided, if anyone knows an actual FIX for this please let me know ASAP Thanks!

under ServerRoot/config/Sponge/global.conf

Edit Sponge.debug.concurrent-entity-checks=false to true.

        # Detect and prevent certain attempts to use entities concurrently.
        # WARNING: May drastically decrase server performance. Only enable this to debug a pre-existing issue

You should disable this as soon as you know which mod is potentially causing the issue, or alternately if it doesn’t tell you which mod is responsible, you should disable it after some time, otherwise you will experience performance issues.