As I’m sure you all know, Minecraft 1.3 has recently been released. This update contains a bug that breaks Z5Craft. Until this bug is fixed, there is no way to fix Z5Craft. The testing server (Z5T1.com:25566) will be down until further notice.
Technical Details of the Bug
Prior to Minecraft 1.3, when a non op player entered a command, the server log said “<Player> tried command <command>”. This mechanism was what Z5Craft used to tell when players entered commands on the server. Unfortunately, Mojang removed/disabled this in Minecraft 1.3. Without this feature, Z5Craft can not work, and there is no easy way to fix Z5Craft without rewriting the majority of the code from scratch.