This is towards servers owners.
If you aren't already aware, Mojang made a recent change that caused an issue with Spigot and MCPC to become apparent. This is not their fault, or anyone elses. Just a bit of unexpected bad luck.
For those of you looking for a fix to constantly crashing servers as of this date, note the following :-
It only affects MCPC and Spigot based servers. (This can include Bungeecord servers if your base server uses Spigot.)
To fix this, Spigot and MCPC have both done fast fixes for the issue. Simply replace your MCPC or Spigot JAR with the following relevant file, and delete your Library folder before starting the server.
MCPC - Click here
< This is a direct download link
Spigot - Click here
Good luck guys, and don't throw out any hate, it's an issue that no-one expected.