I am sorry for the giant lack of information but I can't narrow down any cause for this. I was playing around with command blocks, making a few TestFor things, and then the Repeat command block in charge of one of the Testfor chains just suddenly stops. If I replace the command block with a new one and put the same command, it still doesn't do anything, even if the conditions for it to output something are met.
Sometimes reloading the map works, and sometimes it just stays in nothing.
I would give more information, but the truth is I don't have any more.
Linked issues
Comments
Sounds like MC-86846 then.
Ok I think I found it!
I've recreated this is by doing the following:
1-put a normal command bloxk, then switch it to "Always active"
2-Do ctrl- mouse wheel to have a copy of the block in the inventory
3-Put the new block on the ground
4-Switch the block to "repeat" and put a random command in it (ex: say test)
By doing this, you'll notice that the command block doesn't spam "test" in the chat as it should do!
Comfirmed for 15w50a