When I get a block or item through the /give command, it gives me the block/item, but says "An unknown error occurred while attempting to perform this command."

What I expected to happen was...:
I expected the game to give me a block/item and not do anything except give me it

What actually happened was...:
The game gave the error message.

Steps to Reproduce:
1. make a world or download an existing world
2. do /give [name] [object]
3. watch the chat pump out the red error message.