Bukkit

What steps will reproduce the problem?
1. Make tnt on that if you place a tnt that it will start to activate tnt
2. Place more than 1 tnt so that 1 tnt hurt the other tnt
3.

What is the expected output? What do you see instead?
an error in the console

What version of the product are you using?
newest version

Do you have an error log of what happened?
no, sorry. But it is easy to make the error again.

Please provide any additional information below.