This is a small update. The UniversesPlaceholders.jar file created some confusion. This update simply edits the notes in the config for the prefix-chat option to explain how the feature works with PlaceholderAPI installed. The following paragraph was also hadded to the 5.0 update description;

Special Note for World Prefixes:
The UniversePlaceholders.jar is not a plugin. It should not go in the plugins folder. You only need it if you are using Placeholder API. If you are, put it in the PlaceholderAPI extensions folder. It may not work otherwise. If you are not using PlaceholderAPI this should not be an issue.