CodeChicken/EnderStorage tries to send a packet to the player before the player is connected, so the player is null which causes the server to crash.
Crash report: https://gist.github.com/Time6628/5839e1cf184ecc79871228025a5ba184
Pull request from 1.7.10 with the same/similar NPE: Chicken-Bones/CodeChickenLib#54