For some reason healer blocks crash multiplayer servers when destroyed or placed.
The same is not true with local servers.
I'm using version 1.5.2

Not a block I often check, oops.
Do you have a server error log?

Here you are: http://pastebin.com/2XTAVUaH
I talked about this issue in the FTB irc channel and one moderator check the code, he said there is an error in a call "who try to use single player code instead of the multiplayer one", or something really similar.

Yeah that's what my first thought was

Yep found the error, I will fix this in 5 hours when I get home from work, thanks for the report :)

Ok thanks you, also please fix it in 1.5.2 if you can, I need that version because FTB launcher is not 1.6.2 at the moment and my modpack is in that launcher.
Thank you !

No problem!

Please, tell me when it will be fixed so I can send the fix to FTB to correct the issue in my modpack.
Thank You !