Minecraft - Bukkit Invalid Server Key Fix

by Wahrheit

The Bukkit Team have recently informed us of a fix they have implemented to developer 1.0 builds that resolves the issue with servers giving an "Invalid Key" error. Unfortunately we are not aware of a Vanilla fix for this issue, but you can circumvent it by continuing to reconnect to the server until your connection goes through. For the technical, details are below: When a client joins the server, the server generates a random key and tells the client to connect to the Minecraft master servers saying it has joined the server with that key, if the authentication is correct then it lets them in. The key generated is a random unsigned long integer (0 to 18,446,744,073,709,551,615) and converts it to hexadecimal. However, the client reads the key and converts it back from hexadecimal. When it does this, it reads it as a long integer instead of an unsigned integer which means anything above 9,223,372,036,854,775,807 generated by the server wraps around to a negative and can't be handled by the client. This makes the invalid key error that you all know and love! It's a lot of numbers. We will roll out the next Bukkit Recommended Build once it becomes available but as previously mentioned we will not be uploading any developer builds through ClanForge. If you would like to run one on your server, you can do this through FTP by creating a 1.8 Bukkit profile and uploading the new version of the jar (make sure to name it minecraft_server.jar). Support is not able to offer any help for this process aside from connecting to FTP nor are we able to help with any problems encountered once you are running it due to the unstable nature of the developer builds. We offer great thanks to the Bukkit Team for getting this fixed and look forward to their next Recommended Build!