Players on my server are crashing when they hold/right-click with an item that has a custom lore is in their inventory, when they right-click with a player head in their hand, or when they open their inventory with a custom-lored item.

Problem arose out of nowhere, nothing was changed in the FTP from the time of error. The server was not restarted, nothing was changed. It affected my entire network, we can't find a fix (we've tried disabling certain plugins, removing them, downgrading our server version, etc.)

No console errors received, players receive the message "Disconnected."

My server is completely unplayable with this bug.