Let me ask the Development team if there's any plans to fix that block or if someone knows how to use it.
It may be that when the last server upgrade happened (to minecraft version 1.9.2 and 1.9), this was one of the things that 'broke' when the upgrade happened and is no longer usable because of that. Or maybe not enough users have expressed an interest in getting tutorials for that particular block. It may also be too big of a job for one Development team member to work on (Right now, Development is working on other non-learntomod projects -- updating the servers and making large changes to vox-l or the simulator is a big job). Another possibility is that sending a private message to a certain user (not the whole server) would involve using the console which isn't allowed (permission issues). It could also be that Development has a workaround or is planning to do away with the block during the next big update (whenever that will be) so they haven't spent effort on fixing it.
Meanwhile, and I'm not sure this will help, but have you tried applying the info in this post to the problem? http://forum.learntomod.com/t/how-to-run-mods-of-multiple-users-in-the-new-1-9-servers/64702 That is, using the named_x block.