"Command blocks are not allowed on this server" When it is

Every time in 1.10.2 to 1.11.2 I enable Command Blocks and what does it do? I always get a "Command blocks are not enabled on this server". This is on a Minecraft Server of 1.11.2. It is for making pretend hurricanes and winter storm central for lightning bolts. Yes, I am a very smart computer person, but not as that big if a pro like how to build a OS like Windows. Any help?

-Pengi0007, pongipolarbear in game