I am running the latest version of Spigot from the BuildTools and my server has been crashing even on 1.8.7 and on 1.8.8 Spigot. I have tried looking up reasons for the crashes and could not find a working solution, I have also tried optimizing my server according to threads on the Spigot forums but still no avail. My server is running 6GB of Ram on a Virtual Dedicated Server from NFOServers.

Here is the pastebin of the error message that shows up when the server stops:
http://pastebin.com/t9h07Gvt

My Start.bat code is:

@ECHO OFF
java -Xms3G -Xmx6G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:+CMSIncrementalPacing -XX:+CMSParallelRemarkEnabled -XX:MaxGCPauseMillis=30 -XX:TargetSurvivorRatio=90 -XX:+AggressiveOpts -XX:+UseFastAccessorMethods -XX:+UseBiasedLocking -jar spigot.jar
PAUSE

Sorry if something on here is wrong as this is the first time i've posted a issue on Spigot.