Hi,
Don't touch anything it works

I don't know why but it works
When I put a diamond block, I've got the message : "Protection Block placed". I haven't got this message since the first post, even when I tested with Android yesterday.
I've got information message when I right click on the block and the message "protected" on the block around.
I did nothing, except to test at my work this afternoon (linux client) and it worked. This evening, I tested at my home (Windows client) and it works too
Bye