Describe the bug
ProtocolLib throws an internal error on the start and disables itself.

To Reproduce
Steps to reproduce the behavior:
Use Spigot / Paper 1.8.8 and Java 8

Install ProtocolLib to your server and start the server

Expected behavior
ProtocolLib should not produce this internal error

Screenshots
This is the whole server log: (ProtocolLib dump)
https://just-paste.it/mBC66FSPbZ

Version Info
As ProtocolLib did not even start, the only version info I can provide is the following:

v4.7.0-SNAPSHOT-b524