The Bukkit builds of 2.2 refused to start without PlaceholderAPI installed. If you are on 2.2, update.

The check for PlaceholderAPI lived inside the expansion class itself. Reaching the check meant loading that class, loading it resolved its PlaceholderExpansion superclass, and that class does not exist on a server without PlaceholderAPI. The result was a NoClassDefFoundError during onEnable that took the whole plugin down — leaving the server with no proxy protection at all, which is the worst way for this particular plugin to fail.

The guard now sits in the plugin's main class, before anything names the expansion, and the registration is additionally wrapped so an incompatible PlaceholderAPI version cannot stop the plugin either.

Only the Paper and Folia builds of 2.2 were affected. BungeeCord, Velocity and Sponge never touched that code and are functionally unchanged in this release; they are rebuilt only to keep the version numbers in step.

Everything else is 2.2: consensus scoring across 26 providers, ASN and reverse-DNS signals, behavioural heuristics, trust for regulars, and shared storage through MySQL, MariaDB, PostgreSQL, SQLite, H2 or Redis. See the 2.2 changelog for the details.