Title; produces

java.lang.IncompatibleClassChangeError: Found class org.bukkit.inventory.InventoryView, but interface was expected
    at CoreProtect-22.4.jar//net.coreprotect.listener.player.InventoryChangeListener.onInventoryClick(InventoryChangeListener.java:254)

when running on versions less than 1.21

Purpur issue, resolved in the latest Purpur 1.21 builds.

No I'm on Purpur 1.20.6

Yes, and it’s fixed in the 1.21 builds

My bad there - I meant that (from Spigot's git commit) it looks like the code won't work on any servers with a lower version than 1.21 which is why I created the issue (unless that's out of scope)

The issue isn’t something that can be fixed by CoreProtect.

Options are to use Purpur 1.21, or use Paper 1.20.6

Ah alrighty