I am using Spigot version 1.11.2, and tried installing LibsDisguises and iDisguise. I also installed the latest ProtocolLib because it is a dependency in those libraries. I use them all as an API, I don't install them as a plugin, I just add them to the maven build. Every time I try to disguise using an API (provided by those libraries), I get a NullPointerException. (Yes I registered my command in the plugin.yml, it happens only after I execute the /d command which is disguises me). What I know for sure that it is not something related to the JAR itself, because it includes all the libraries, I think it is something in my version, or something else.