I've been working on a minigame map. I generated the world Superflat on Survival with Cheats so I could go into Creative to build it.

My Redstone setup for this is as follows:
Player presses button
Redstone trail goes to a command block: /say Game starts in 5...
Trail continues to command block: /say 4...
Trail continues to command block: /say 3...
Trail continues to command block: /say 2...
Trail continues to command block: /say 1...
Trail continues to 3 command blocks that activate simultaneously.
Command Block A: /say Go!
Command Block B: /tp @a (coords)
Command Block C: /spawnpoint @a (coords)

A and B work fine, but C doesn't do anything. It's basically dead, it doesn't even say that it set the spawnpoint of all players. I tested to see if I just placed it in a bad spot and changed the command, and it worked with that. I put /spawnpoint back in and it didn't do anything still. Unfortunately, my map won't work until this issue is fixed.