1.set up rf system
2.set up a constructor and destructor facing the same block, configuration isn't important, but they have to face the same block.
3.set a block you have X of to be placed by constructor and watch the numbers go up X+1.every time the destructor breaks it again.
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Does this issue occur on a server? Yes
Already fixed in newer versions
make sure you are on the latest version before reporting
i searched through the issue tracker and didn't find it fixed, so i just thought just in case