This release fixes a few reported security issues, in addition to some other minor bug fixes & performance tweaks. This version is fully compatible with all previous 1.8 versions, but it is still highly recommend to update to 1.8.4 as soon as possible.
Bug fixes:
Please make sure that you are in the correct server mode (online mode/offline mode) when you start the 1.8.4 server for the first time, because profiles are not compatible between these two server modes.
Download Links:
Cross-platform server jar: https://minecraftlucky.com/dowload/file-3748
Cross-platform server windows exe: https://minecraftlucky.com/dowload/file-3749