#1 - Sept. 17, 2013, 6:16 p.m.
Blizzard Post

If you own a custom arena, you may notice that some commands may not be working. This is a temporary change that will be reverted upon the in the next regular patch in two weeks. The reason behind this is to slow down the speed that some players are acquiring glory with the use of these commands.

There is an upcoming change that will allow custom arena owners to enable or disable these commands. When enabled, progression will be disabled.

Affected commands:
/gamestart
/gameend
/setscore