Kong Ming

Had the same problem when one of my players built an engine and crashed the server. Followed the steps to replace the buildcraft API in the railcraft archive. This got the server running again no problem, BUT all railcraft parts in the world have vanished and any attempt to create new ones results in a crash for the client. I've also attempted this with a client that has done the same API replacement to their Tekkit files. Has anyone else encountered this? Other posters seem only concerned with fixing IC2 and buildcraft issues. Does anyone else use railcraft?